CN109714110B - W-state-based controllable OAM quantum invisible state transfer system and method - Google Patents

W-state-based controllable OAM quantum invisible state transfer system and method Download PDF

Info

Publication number
CN109714110B
CN109714110B CN201811651238.5A CN201811651238A CN109714110B CN 109714110 B CN109714110 B CN 109714110B CN 201811651238 A CN201811651238 A CN 201811651238A CN 109714110 B CN109714110 B CN 109714110B
Authority
CN
China
Prior art keywords
oam
sam
state
polarization
entanglement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811651238.5A
Other languages
Chinese (zh)
Other versions
CN109714110A (en
Inventor
郭邦红
曾炎颖
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong Yukopod Technology Development Co.,Ltd.
Original Assignee
South China Normal University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by South China Normal University filed Critical South China Normal University
Priority to CN201811651238.5A priority Critical patent/CN109714110B/en
Publication of CN109714110A publication Critical patent/CN109714110A/en
Priority to PCT/CN2019/129506 priority patent/WO2020140854A1/en
Application granted granted Critical
Publication of CN109714110B publication Critical patent/CN109714110B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/70—Photonic quantum communication

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
  • Optical Communication System (AREA)

Abstract

The invention discloses a W-state-based controllable OAM quantum invisible state transfer system, which comprises an Alice sending end and a Bob receiving end, wherein Alice comprises a mixed entanglement unit, an entanglement exchange unit, a Path analysis unit and an SAM analysis unit, and Bob comprises an OAM analysis unit. The entanglement exchange unit is used for carrying out entanglement exchange on the SAM-OAM entangled photon pair, the SAM-Path entangled photon pair and the SAM-SAM entangled photon pair to obtain two W states which have equal probability and are mutually symmetrical, and one of the two W states is randomly selected as a quantum channel; the OAM analysis unit is used for OAM analysis, and Alice can remotely control OAM generation of Bob photons by using electric field tuning. The invention is an open target invisible state, can form an asymmetric light quantum network, realizes a quantum invisible state which can be remotely controlled, has high dimensionality, can be expanded and is safer, and has great application prospect.

Description

W-state-based controllable OAM quantum invisible state transfer system and method
Technical Field
The invention belongs to the field of quantum information and quantum communication, and particularly relates to a controllable OAM quantum invisible state transfer system based on a W state.
Background
Quantum invisible transport (Quantum telecommunications) is an important communication method. In the quantum invisible transmission state, two communication parties far away from each other share one pair of entangled particles, wherein one party carries out Bell state measurement on the quantum state particles to be transmitted and the entangled particles in hands of the other party, then the other party is informed of the measurement result, and the other party carries out corresponding unitary operation according to the obtained information. In 1993, Bennett et al first proposed the concept of quantum invisible transport states. In 1997, Bouwmeester et al first succeeded experimentally as a quantum channel with entangled photon pairs, revealing the possibility of transmitting quantum states without the photons themselves being transmitted. In 1998, Martini et al used Type-II parametric down-conversion to generate EPR entangled pairs with the same frequency and mutually orthogonal polarization states as quantum channels. In the two successful experiments, a single photon polarization state is adopted as a quantum state to be transmitted, but the signal-to-noise ratio obtained by the experiment is not high due to the extremely low detection efficiency of the detector on the single photon; most invisible transmission schemes are based on single-degree-of-freedom quantum entanglement, and due to inevitable decoherence effects caused by external conditions such as noise, attenuation and the like in a quantum channel, the communication quality and the detection efficiency are low, and the feasibility of quantum states in the actual remote transmission process is influenced.
In recent years, research on remote regulation and open-type objective invisible states also becomes a hotspot in the field of quantum information, and in 2009, chenkuai et al propose an electrically adjustable and spin-related integer or non-integer orbital angular momentum generator; in 2011, a GHZ state multi-degree-of-freedom open type target invisible state is provided. However, the quantum state invisible transmission scheme is still greatly limited in transmission distance, communication quality, anti-interference capability and the like, and as a brand new communication mode, the quantum state invisible transmission scheme cannot be applied to the actual quantum communication field.
Disclosure of Invention
The invention provides a quantum invisible state transfer system based on a SAM-Path-OAM mixed W state. The OAM generation of Bob is remotely controlled by Alice, and according to the spin state of another photon and the linear momentum state of photon 2 which are independently sent by Carol, the OAM state of the photon in the hand of a receiver Bob can be remotely regulated and controlled by the sender Alice through electric field tuning, and the open invisible state can form an asymmetric optical quantum network, so that the quantum invisible state which can be remotely controlled, has high dimensionality, can be expanded and is safer can be realized, and the method has a great application prospect.
In order to solve the above disadvantages, the present invention provides a W-state-based controllable OAM quantum invisible state transfer system, including: alice end and Bob end, Alice end includes: mixed entanglement unit, entanglement exchange unit, Path analysis unit and SAM analysis unit, mixed entanglement unit includes: the SAM-OAM mixed entanglement subunit, the SAM-Path mixed entanglement subunit and the SAM-SAM mixed entanglement subunit are connected in series; the Bob end comprises an OAM analysis unit;
the SAM-OAM mixed entanglement subunit comprises a first pumping source, a first prism, a first BBO crystal, a first total reflector and a second total reflector which are sequentially arranged, and a first half-wave plate, an OAM generator and a first single-mode fiber are sequentially arranged on the reflection side of the first total reflector;
pump light generated by the first pump light source passes through the first prism and the first BBO crystal to generate a first orbital angular momentum entangled photon pair, and the first orbital angular momentum entangled photon pair is divided into first signal light and first idle light; the first signal light is output to an OAM analysis unit through a second total reflection mirror; after the first idle light sequentially passes through the first total reflector, the first half-wave plate, the OAM generator and the first single-mode fiber, the first orbital angular momentum entangled photon is converted into a polarization-orbital angular momentum entangled photon pair;
the SAM-Path mixed entanglement subunit comprises a second prism, a second BBO crystal and a fifth total reflector which are arranged in sequence, and a third total reflector and a fourth total reflector which are arranged between the second BBO crystal and the fifth total reflector, wherein the reflection side of the third total reflector is also provided with a first Q-plate phase plate, a second single-mode optical fiber and a first lambda/4 wave plate in sequence;
the part of the pump light irradiated on the first BBO crystal transmits through the first BBO crystal to generate a transmission light beam, the transmission light beam is reflected to the second BBO crystal again through the fifth total reflector to generate a second orbital angular momentum entangled photon pair, the second orbital angular momentum entangled photon pair is divided into a second signal light and a second idle light, and the second signal light is output to the Path analysis unit through the fourth total reflector; after the second idle light sequentially passes through a third total reflector, a first Q-plate phase plate, a second single-mode fiber and a first lambda/4 wave plate, second orbital angular momentum entangled photons are converted into polarization-linear momentum entangled photon pairs;
the SAM-SAM mixed entanglement subunit is used for generating mutually vertical polarization entangled photon pairs, dividing the mutually vertical polarization entangled photon pairs into third signal light and third idle light, sending the third idle light to the entanglement exchange unit, and sending the third signal light to the SAM analysis unit;
the entanglement exchanging unit entangles and exchanges the polarization-orbital angular momentum entangled photon pair, the polarization-linear momentum entangled photon pair and the mutually vertical polarization entangled photon pair to obtain multi-degree-of-freedom hybrid entangled W-state photons;
the OAM analysis unit comprises a first spatial light modulator and a third single-photon detector, and the third single-photon detector performs OAM analysis on the received first signal light;
the Path analysis unit comprises a first computation hologram, two total reflectors and a third beam splitter which are sequentially arranged, wherein the two total reflectors comprise a ninth total reflector and a tenth total reflector, the output end of the third beam splitter is also connected with a fourth single-photon detector and a fifth single-photon detector, and the fourth single-photon detector and the fifth single-photon detector perform Path analysis on the received second signal light; wherein, the operator that the first calculation hologram adopted is:
Figure BDA0001933047260000031
the SAM analysis unit comprises a third single-mode fiber, a second half-wave plate, a horizontal polarizer and a sixth single-photon detector which are sequentially arranged, and the sixth single-photon detector performs SAM analysis on the received third idle light.
Preferably, the OAM generator is composed of two conjugated zinc telluride crystals with 90 relative rotation of their transverse crystalline X-Y axes in helical phase.
Another preferred Q-plate phase plate is a Pancharatnam-Berry phase plate, made of uniaxially birefringent nematic liquid crystal material.
Preferably, the SAM-SAM entanglement subunit comprises a second pump source, a third prism, a first PPKTP crystal, a sixth holophote and a seventh holophote, which are arranged in sequence;
the pumping light generated by the second pumping source generates mutually vertical polarization entangled photon pairs after passing through the first PPKTP crystal, the mutually vertical polarization entangled photon pairs are divided into third signal light and third idle light, the third signal light is output to the SAM analysis unit after passing through the seventh holophote, and the third idle light enters the entanglement exchange unit after changing the direction after passing through the sixth holophote.
Preferably, the entanglement switching unit comprises an eighth total reflection mirror, a first beam splitter, a second beam splitter and a polarization beam splitter which are arranged in sequence, and the output end of the polarization beam splitter is further connected with a first single-photon detector and a second single-photon detector;
the first idle light output by the first single-mode fiber reaches the first beam splitter after passing through the eighth holophote, the second idle light output by the first lambda/4 wave plate directly reaches the first beam splitter, and the first beam splitter couples each arriving photon and outputs the coupled photon to the second beam splitter; the third idle light output by the sixth total reflection mirror directly reaches the second beam splitter, and the second beam splitter couples each arriving photon and outputs the coupled photon to the polarization beam splitter;
the polarization beam splitter divides photons reaching the polarization beam splitter into horizontal polarized photons and vertical polarized photons, wherein the horizontal polarized photons enter the first single photon detector, and the vertical polarized photons enter the second single photon detector.
Preferably, the first total reflector and the second total reflector are located on the same side of the first BBO crystal, and have an included angle in space;
the fifth total reflector is arranged opposite to the second BBO crystal, and the third total reflector and the fourth total reflector form an included angle in space.
Preferably, the sixth total reflecting mirror and the seventh total reflecting mirror are located on the same side of the first PPKTP crystal, and have an included angle in space.
8. A controllable OAM quantum invisible state transfer method based on a W state is characterized by comprising the following steps:
s1: respectively generating a polarization-orbital angular momentum entangled photon pair, a polarization-linear momentum entangled photon pair and a mutually vertical polarization entangled photon pair by using an SAM-OAM mixed entanglement subunit, an SAM-Path mixed entanglement subunit and an SAM-SAM mixed entanglement subunit;
s2: respectively sending the polarization-orbital angular momentum entangled photon pair, the polarization-linear momentum entangled photon pair and the mutually vertical polarization entangled photon pair generated in the step S1 to an entanglement switching unit, and converting in the entanglement switching unit to obtain multi-degree-of-freedom hybrid entangled W-state photons;
s3: the Alice terminal randomly selects a W state as a quantum channel of the invisible transmission state, performs Bell state measurement according to the selected W state, sends the Bell state measurement result to the Bob terminal through a classical channel, and enters the step S4;
s4: the Bob end carries out local unitary transformation according to the Bell state measurement result;
s5: OAM analysis, Path analysis and SAM analysis are performed by an OAM analysis unit, a Path analysis unit and a SAM analysis unit, respectively.
9. The method of claim 8, wherein the W-state-based controllable OAM quantum invisible state transfer method is characterized in that:
step S1 includes the following steps:
s1.1: converting a part of pump light sent by a first pump light source into a first orbital angular momentum entangled photon pair through a first prism and a first BBO crystal, forming a transmission beam by a part of the pump light, and dividing the first orbital angular momentum entangled photon pair into first signal light and first idle light;
s1.2: reflecting the first signal light to the OAM analysis unit through a second total reflection mirror; converting the first orbital angular momentum entangled photon into a polarization-orbital angular momentum entangled photon pair sequentially through a first total reflector, a first half-wave plate, an OAM generator and a first single-mode fiber;
s1.3: converting the transmitted beam formed in the step S1.1 into a second orbital angular momentum entangled photon pair through a fifth total reflection mirror and a second BBO crystal, and dividing the second orbital angular momentum entangled photon pair into a second signal light and a second idle light;
s1.4: reflecting the second signal light to the Path analysis unit through a fourth total reflection mirror; and the second orbital angular momentum entangled photon is converted into a polarization-linear momentum entangled photon pair through a third total reflection mirror, a first Q-plate phase plate, a second single-mode fiber and a first lambda/4 wave plate in sequence.
10. The method of claim 8 or 9, wherein the method comprises:
step S1 further includes the steps of:
s1.1': the pump light sent by the second pump source is converted into mutually vertical polarization entangled photon pairs through a third prism and the first PPKTP crystal, and the mutually vertical polarization entangled photon pairs are divided into third signal light and third idle light;
s1.2': the third signal light is reflected to the SAM analysis unit by a seventh total reflection mirror.
Compared with the prior art, the invention has the beneficial effects that:
1. the generating system has simple structure and convenient use, can stably generate two kinds of entangled W-state photons with equal probability mutually symmetrical, and can randomly select the quantum state for loading information during the communication process by two communication parties, so that an eavesdropper cannot determine whether the intercepted information is effective or not. Moreover, when an eavesdropper intercepts partial photons or loses particles which can load bit information for some reason, the rest particles can still carry out communication, for example, when the photons 1-1' are lost, entanglement still exists between 2-2' and 3-3', and the loaded information can still carry out effective communication; the entangled W-state photons generated by the invention are mixed and entangled based on a plurality of degrees of freedom, which is beneficial to improving the safety of quantum communication, has strong entanglement characteristic and bit loss resistance in a free space and an optical fiber, and reduces the influence of factors such as noise, decoherence and the like.
2. The invention adopts the signal light carrying orbital angular momentum to carry out entanglement preparation, thereby realizing the characteristics of high dimensionality and capability of forming an infinite dimensional vector space. The quantum information capacity is up to I ═ log2m+log22+log 22＝log2m +2(m is the number of l, l is 0, ± 1, ± 2, ± 3 …), which can greatly increase the information carrying capacity of photons and increase the channel capacity of quantum network compared with other invisible state schemes. And moreover, the beam carrying the OAM has the advantages that the singularity of the spiral beam can reduce the influence of atmospheric turbulence on the beam quality, the light intensity distribution of a focal plane, the OAM detection probability and the like, the OAM state is kept unchanged when the OAM rotates around the propagation direction, and Alice and Bob do not need to adjust a reference system in real time, so that the quantum communication quality in a free space is improved.
3. The invention can realize the high-dimensional and expandable high-capacity quantum information processing of SAM-Path-OAM three-photon system entanglement, Alice can remotely prepare the OAM state of Bob photons in a high-dimensional Hilbert space by using half-integer vortex light, and the OAM generation of Bob is remotely and electrically adjustable by Alice and depends on the Carol photon polarization state and the linear momentum state of photon 2.
Drawings
Fig. 1 is a schematic block diagram of a W-state-based controllable OAM quantum invisible state transfer system according to the present invention;
fig. 2 is a schematic structural diagram of a W-state-based controllable OAM quantum invisible state transfer system according to the present invention;
fig. 3 is a preparation diagram of an OAM-Path-SAM mixed entangled W state according to the present invention;
fig. 4 is an analysis device of a controllable OAM quantum invisible state transfer system based on a W state according to the present invention;
FIG. 5 is a diagram of the theoretical result of OAM density matrix of Bob when Carol spin state is | φ > - | H > according to the present invention.
Wherein, fig. 1 to 5 include:
a SAM-OAM mixed entanglement subunit 1, a first prism 101, a first BBO crystal 102, a first total reflection mirror 103, a second total reflection mirror 104, a first half wave plate 105, an OAM generator 106, a first single mode fiber 107,
A SAM-Path mixed entanglement subunit 2, a second prism 201, a second BBO crystal 202, a third total reflection mirror 203, a fourth total reflection mirror 204, a fifth total reflection mirror 205, a first Q-plate phase plate 206, a second single-mode fiber 207, a first lambda/4 wave plate 208, a second lambda/4 wave plate,
A SAM-SAM mixed entanglement subunit 3, a third prism 301, a first PPKTP crystal 302, a sixth total reflection mirror 303, a seventh total reflection mirror 304,
An entanglement exchanging unit 4, an eighth total reflection mirror 401, a first beam splitter 402, a second beam splitter 403, a polarization beam splitter 404, a first single-photon detector 405, a second single-photon detector 406,
An OAM analysis unit 5, a first spatial light modulator 501, a third single-photon detector 502,
A Path analysis unit 6, a first computer generated hologram 601, a ninth total reflection mirror 602, a tenth total reflection mirror 603, a third beam splitter 604, a fourth single-photon detector 605, a fifth single-photon detector 606,
A SAM analysis unit 7, a third single mode fiber 701, a second half-wave plate 702, a horizontal polarizer 703, and a sixth single-photon detector 704.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.
Example one
A controllable OAM quantum invisible state transfer system based on a W state, as shown in fig. 1 and 2, comprising: including Alice end and Bob end, Alice end includes: a hybrid entanglement unit, an entanglement exchange unit 4, a Path analysis unit 6 and a SAM analysis unit 7, wherein the Bob end comprises an OAM analysis unit 5; the hybrid entangling unit includes: a SAM-OAM mixed entanglement subunit 1, a SAM-Path mixed entanglement subunit 2, and a SAM-SAM mixed entanglement subunit 3.
Specifically, the SAM-OAM hybrid entanglement unit 1 includes a first pump source, a first prism 101, a first BBO crystal 102, a first total reflector 103, and a second total reflector 104, which are sequentially arranged, and a first half-wave plate 105, an OAM generator 106, and a first single-mode fiber 107 are further sequentially arranged on a reflection side of the first total reflector 103. The first total reflector and the second total reflector are positioned on the same side of the BBO crystal, and an included angle is formed in space. The first pump source is used for generating pump light and providing an input pulse signal for the first BBO crystal 102, and the first BBO crystal 102 is used for Type-I parametric down-conversion to obtain a photon pair with high-dimensional orbital angular momentum entanglement.
Pump light generated by the first pump light source passes through the first prism 101 and the first BBO crystal 102 to generate a first orbital angular momentum entangled photon pair, and the first orbital angular momentum entangled photon pair is divided into first signal light and first idle light; the first signal light is output to an OAM analysis unit through a second total reflection mirror; after the first idle light sequentially passes through the first total reflection mirror 103, the first half-wave plate 105, the OAM generator 106 and the first single-mode fiber 107, the first orbital angular momentum entangled photon is converted into a polarization-orbital angular momentum entangled photon pair. Therefore, Alice converts the primary OAM-OAM entanglement into a SAM-OAM mixed entanglement, and accordingly the corresponding relation between the two-dimensional spinning Hilbert space of Alice is established. To do this, Alice first rotates the horizontal linear polarization of the photon by 45 ° using a half-wave plate 105, and sends the photon to the OAM generator 106 as described above.
Specifically, the SAM-Path hybrid entanglement subunit 2 includes a second prism 201, a second BBO crystal 202, and a fifth total reflection mirror 205, which are sequentially arranged, and a third total reflection mirror 203 and a fourth total reflection mirror 204, which are arranged between the second BBO crystal 202 and the fifth total reflection mirror 205, and a first Q-plate phase plate 206, a second single-mode fiber 207, and a first λ/4 wave plate 208 are sequentially arranged on a reflection side of the third total reflection mirror 203. The fifth total reflecting mirror 205 is arranged opposite to the second BBO crystal 202, and the third total reflecting mirror 203 and the fourth total reflecting mirror 204 form an included angle in space.
The part of the pump light irradiated on the first BBO crystal 102 transmits through the first BBO crystal 102 to generate a transmitted light beam, the transmitted light beam is reflected again to the second BBO crystal through the fifth total reflector 205 to generate a second orbital angular momentum entangled photon pair, and the second orbital angular momentum entangled photon pair is divided into a second signal light and a second idle light; the second signal light passes through the fourth total reflection mirror 204, the fourth total reflection mirror 204 reflects the light beam incident thereon, the light beam is used for changing the propagation direction of the light beam, and the light beam with the changed direction is output after being sent to the Path analysis unit 6; the second idle light sequentially passes through the third total reflector 203, the first Q-plate phase plate 206, the second single-mode fiber 207 and the first λ/4 wave plate 208, and then the second orbital angular momentum entangled photon is converted into a polarization-linear momentum entangled photon pair. The Q-plate phase plate 206 converts the orbital angular momentum entangled photon pair generated by the Type-I into entangled association between the orbital angular momentum and the spin angular momentum, the second single-mode fiber 207 selects idle light transformed by the Q-plate phase plate 206, Gaussian light with an idle light mode of zero is screened to pass through, and the first lambda/4 wave plate 208 converts the spin polarized photon into a horizontal vertical polarized photon, so that a polarization-linear momentum entangled photon pair is formed.
Preferably, the Q-plate phase plate 206Pancharatnam-Berry phase plate is made of a uniaxially birefringent nematic liquid crystal material; in a transverse x-y plane, the orientation of the optical axis has a certain spatial distribution, and a fixed phase delay is arranged in the direction of the z axis; in a polar coordinate system, the optical axis orientation distribution can be expressed as: α (r, φ) ═ q φ + α0(wherein q and α0Are all constants).
Specifically, the SAM-SAM entanglement subunit includes a second pump source, a third prism 301, a first PPKTP crystal 302, a sixth total reflector 303, and a seventh total reflector 304, which are sequentially arranged; the sixth total reflecting mirror 303 and the seventh total reflecting mirror 304 are located on the same side of the first PPKTP crystal 302, and have an included angle in space.
The pump light generated by the second pump source generates mutually perpendicular polarization entangled photon pairs after passing through the first PPKTP crystal 302, the mutually perpendicular polarization entangled photon pairs are divided into third signal light and third idle light, the third idle light changes direction after passing through the sixth holophote 303 and enters the entanglement exchanging unit 4, and the third signal light is output to the SAM analysis unit 7 after passing through the seventh holophote 304.
Specifically, the entanglement switching unit 4 includes an eighth total reflection mirror 401, a first beam splitter 402, a second beam splitter 403, and a polarization beam splitter 404, which are sequentially arranged, and an output end of the polarization beam splitter 404 is further connected with a first single-photon detector 405 and a second single-photon detector 406;
the first idle light output by the first single-mode fiber 107 passes through the eighth total reflection mirror 401 and then reaches the first beam splitter 402, the second idle light output by the first λ/4 plate 208 directly reaches the first beam splitter 402, and the first beam splitter 402 couples each arriving photon and outputs the coupled photon to the second beam splitter 403; the third idle light output by the sixth total reflection mirror 303 directly reaches the second beam splitter 403, and the second beam splitter 403 couples each arriving photon and outputs the coupled photon to the polarization beam splitter 404. The polarization beam splitter 404 is configured to separate the polarization of the composite light beam, that is, the polarization beam splitter 404 splits the photons reaching it into horizontally polarized photons and vertically polarized photons, where the horizontally polarized photons enter the first single photon detector 405, and the vertically polarized photons enter the second single photon detector 406. The first single-photon detector 405 is used to measure the number of photons in the horizontal polarization state; the second single-photon detector 406 is used for measuring the photon number in the vertical polarization state, and different W states can be obtained according to different readings of the first single-photon detector 405 and the second single-photon detector 406.
The W state is two W states which are SAM-Path-OAM and have three different degrees of freedom, equal probability and symmetry with each other, and one W state is randomly selected to serve as a quantum channel. The Alice end can remotely control the generation of OAM of photons at the Bob end by utilizing electric field tuning, and the Bob end can convert the OAM generating operator of the Bob end into an OAM generating operator corresponding to local unitary transformation after applying corresponding local unitary transformation on the freedom degree of photons OAM of the Bob end according to Bell State Measurement (BSM) results sent by the Alice end through a classical channel
Figure BDA0001933047260000081
And the same operator is adopted, so that the invisible state transfer process is completed.
Specifically, the OAM analysis unit 5 includes a first spatial light modulator 501 and a third single-photon detector 502, and is configured to perform OAM analysis on the received first signal light.
The Path analysis unit 6 includes a first Computer Generated Hologram (CGH)601, two total reflectors and a third beam splitter 604, which are sequentially arranged, the two total reflectors include a ninth total reflector 602, a tenth total reflector 603 and a third beam splitter 604, and an output end of the third beam splitter 604 is further connected with a fourth single-photon detector 605 and a fifth single-photon detector 606, which are used for performing Path analysis on the received second signal light. Among them, CGH (Computer-generated phase hologram) converts a spiral phase beam carrying orbital angular momentum into a beam carrying linear momentum using a fork-shaped diffraction grating.
The SAM analysis unit 7 includes a third single mode fiber 701, a second half-wave plate 702, a horizontal polarizer 703, and a sixth single photon detector 704, which are sequentially arranged, and is configured to perform SAM analysis on the received third idle light.
A controllable OAM quantum invisible state transfer method based on a W state comprises the following steps:
s1: respectively generating a polarization-orbital angular momentum entangled photon pair, a polarization-linear momentum entangled photon pair and a mutually vertical polarization entangled photon pair by using an SAM-OAM mixed entanglement subunit, an SAM-Path mixed entanglement subunit and an SAM-SAM mixed entanglement subunit;
s2: respectively sending the polarization-orbital angular momentum entangled photon pair, the polarization-linear momentum entangled photon pair and the mutually vertical polarization entangled photon pair generated in the step S1 to an entanglement switching unit to obtain multi-degree-of-freedom hybrid entangled W-state photons;
s3: the Alice terminal randomly selects a W state as a quantum channel of the invisible transmission state, performs Bell state measurement according to the selected W state, sends the Bell state measurement result to the Bob terminal through a classical channel, and enters the step S4;
s4: the Bob end carries out local unitary transformation according to the Bell state measurement result;
s5: OAM analysis, Path analysis and SAM analysis are performed by an OAM analysis unit, a Path analysis unit and a SAM analysis unit, respectively.
Further, step S1 includes the following steps:
s1.1: converting a part of pump light sent by a first pump light source into a first orbital angular momentum entangled photon pair through a first prism and a first BBO crystal, forming a transmission beam by a part of the pump light, and dividing the first orbital angular momentum entangled photon pair into first signal light and first idle light;
s1.2: reflecting the first signal light to the OAM analysis unit through a second total reflection mirror; converting the first orbital angular momentum entangled photon into a polarization-orbital angular momentum entangled photon pair sequentially through a first total reflector, a first half-wave plate, an OAM generator and a first single-mode fiber;
s1.3: converting the transmitted beam formed in the step S1.1 into a second orbital angular momentum entangled photon pair through a fifth total reflection mirror and a second BBO crystal, and dividing the second orbital angular momentum entangled photon pair into a second signal light and a second idle light;
s1.4: reflecting the second signal light to the Path analysis unit through a fourth total reflection mirror; and the second orbital angular momentum entangled photon is converted into a polarization-linear momentum entangled photon pair through a third total reflection mirror, a first Q-plate phase plate, a second single-mode fiber and a first lambda/4 wave plate in sequence.
As above, step S1 further includes the steps of:
s1.1': the pump light sent by the second pump source is converted into mutually vertical polarization entangled photon pairs through a third prism and the first PPKTP crystal, and the mutually vertical polarization entangled photon pairs are divided into third signal light and third idle light;
s1.2': reflecting the third signal light to the SAM analysis unit by a seventh holophote;
s1.3': generating a polarization-orbital angular momentum entangled photon pair, namely a 1-1 'photon pair (1 is OAM photon, and 1' is polarized photon) by using the SAM-OAM mixed entangled subunit; the SAM-Path mixed entanglement subunit generates a polarization-linear momentum entangled photon pair, namely a 2-2 'photon pair (2 is a linear momentum photon, and 2' is a polarization photon); the SAM-SAM mixed entanglement subunit generates polarization entangled photon pairs which are vertical to each other, namely 3-3 'photon pairs (3 is polarized photon, and 3' is polarized photon).
The specific working principle of the invention is as follows: in the system, as shown in fig. 3, when the pump light generated by the first pump light source is a gaussian light beam under the conversion of the Type-I parameter, the pump light generates a first orbital angular momentum entangled photon pair after passing through the first prism 101 and the first BBO crystal 102, and the obtained first orbital angular momentum entangled photon pair can be represented as:
|φ>＝ΣmCm|m>1<-m|2(1)
wherein, 1 and 2 in the formula (1) represent a first signal light and a first idle light respectively, and m represents an n-order OAM eigenmode;
the formula (1) shows that:
Figure BDA0001933047260000101
and the photon that Type-II parameter down conversion produced is each other vertically polarization entanglement, and pump light produces each other vertically polarization entanglement photon pair after passing through first PPKTP crystal 302, and the corresponding entanglement attitude is:
Figure BDA0001933047260000102
| H > and | V > are spin eigenstates, representing horizontal and vertical polarization, respectively.
For the 2-2' group, the second idler light with helical phase passes through the diffraction grating (i.e., Q-plate phase plate 206) to obtain exp (il φ) → exp [ i (l φ) → exp0±lh)]The optical beam then passes through a second single mode fiber 207, which acts selectively on the zeroth order gaussian light, so that the initial information loaded by OAM is transmitted to the diffraction path with | k |+>And | k_>In the linear momentum state of (c), if l0±lhAt 0, the diffracted beam will be focused and thus can be efficiently coupled to the SMF (second single mode fiber 207). The first computed hologram 601 corresponds to an operator represented as:
Figure BDA0001933047260000103
the Q-plate phase plate 206 is made of uniaxial refractive liquid crystal, the orientation of the optical axis has certain spatial distribution in the transverse x-y plane, and a fixed phase delay is arranged in the z-axis direction; in a polar coordinate system, the optical axis orientation distribution can be expressed as: α (r, φ) ═ q φ + α0(wherein q and α0Are all constants. )
When α 0 is 0, for having OAM is
Figure BDA0001933047260000104
Is represented by the operator:
Figure BDA0001933047260000105
where | L > and | R > are spin eigenstates, representing left-hand polarization and right-hand polarization, respectively.
As shown in FIG. 3, for the 1-1 'group, Alice converts the preliminary OAM-OAM entanglement into a SAM-OAM hybrid entanglement, thereby creating Alice's two-dimensional spin Hilbert (transform)) The correspondence between the spaces. To this end, Alice first rotates the horizontal linear polarization of the photons by 45 using the first half-wave plate 105, i.e.
Figure BDA0001933047260000111
And then sends the photons to OAM generator 106 as previously described. The OAM generator 106 is composed of two conjugated zinc telluride (ZnTe) spiral phase compositions (SPP)1And SPP2) Two SPPsSConfigured so that their transverse crystallographic X-Y axes have a relative rotation of 90 deg., and furthermore the entrance and exit facets are coated with a transparent electrode so that an external voltage U can be applied to the crystal. When an external electric field is applied, according to the theory of index ellipsoids, the index ellipsoids of ZnTe are distorted after undergoing the Pockels effect (Pockels effect). Of course, the orbital angular momentum generator of Alice is local at this time, and can be described as follows:
Figure BDA0001933047260000112
here, exp (ik)0n0ls) Are insignificant propagation constants and are therefore ignored. This time Alice uses the spin degrees of freedom of the photons in her hand to locally control the orbital angular momentum degrees of freedom of the same photon. Thus, after local manipulation by Alice, the two-photon entangled state becomes:
Figure BDA0001933047260000113
alice then uses SMF (first single mode fiber 107) to exclusively select a gaussian beam with zero fundamental mode, and this photon is then reflected by a mirror (eighth holo-mirror 401) that reflects the spiral of incident photons, i.e. the spiral of incident photons
Figure BDA0001933047260000114
From the "forward wave model", we know that this projection measurement simultaneously forces the two-photon states to collapse into a mixed mode:
Figure BDA0001933047260000115
for the 2-2' group, after photon 2 passes through the CGH (computer generated hologram) and QP phase plate, the quantum state becomes:
Figure BDA0001933047260000116
and then through the screening of SMF (second single mode fiber 107) and the action of the first λ/4 plate 208. The first λ/4 plate 208 converts the spin polarization state to a horizontal vertical polarization state, and the quantum state of photon pair 2-2' changes as:
Figure BDA0001933047260000117
the second beam splitter 403 couples three idle light paths to the same path, the polarization beam splitter 404 separates the polarization of the coincident light beams, the first single-photon detector 405 measures the number of photons in the horizontal polarization state, and the second single-photon detector 406 measures the number of photons in the vertical polarization state, so that the multi-degree-of-freedom particle system formed by the 1-1', 2-2', and 3-3' entangled photon pairs can be expressed as (without considering the normalization coefficient):
Figure BDA0001933047260000121
(1) if the single photon detectors 405, 406 detect two H (horizontal polarization states), the system collapses to W1′In the state:
W1′＝exp(-iQ1′π)(|(+Q1′)1(k+)2V3>+|(+Q1′)1(k-)2H3>)+exp(iQ1′π)|(-Q1′)1(k-)2V3>(12)
(2) if the single photon detectors 405, 406 detect two V (vertical polarization states), the system collapses to W2′In the state:
W2′＝exp(-iQ1′π)|(+Q1′)1(k+)2H3>+exp(iQ1′π)(|(-Q1′)1(k+)2V3>+|(-Q1′)1(k_)2H3>) (13)
alice can randomly send two forms of W states (W)1′And W2′) And for Bob, the two parties determine that a certain W state is an effective information carrier in the communication process by negotiating or sharing a random code.
We randomly select the quantum state W1′Or W2′Quantum channels as invisible state schemes. If the photon pair 1, 2, 3 is at W1′When, let the photon spin state of Carol (photon 4) be an arbitrary polarization state | φ>4＝α|H>+β|V>(α2+β21) as shown in fig. 4, after being developed in Bell base:
Figure BDA0001933047260000122
wherein
Figure BDA0001933047260000123
These four equations are the four Bell states (BellStates, used to describe the four most entangled states of a two-qubit system).
As shown in equation (14), the method we transmit quantum information is: alice performs BSM operations on photons of both photons (photon 3) and Carol (photon 4) that it holds. If the BSM result is | Φ+>34Then we get photons 1 and 2, i.e. the first line of equation (14), i.e. the local operator of the OAM generator at Alice side as described in equation (8) has been transferred to Bob side in this form:
Figure BDA0001933047260000124
it is clear from equation (15) that OAM generation by Bob is remotely and electrically tunable by Alice and depends on Carol photons and the linear momentum states of photons 2, generallyIn other words, the probability of occurrence of all four Bell states is 25%. According to the BSM result sent by Alice through the classical channel, Bob can convert the OAM generating operator into the sum after applying corresponding local unitary transformation on the OAM degree of freedom of the photon
Figure BDA0001933047260000132
And the same operator is adopted, so that the invisible state transfer process is completed.
Experimentally, the projection of equation (15) is actually a post-selection of all detectors corresponding to photons 1, 2, 3 and 4 being present simultaneously, which is usually achieved by coincidence logic of all detectors. The information on any photon can be further read out by making local measurements on other photons. If a path analysis is performed for photon 2:
Figure BDA0001933047260000131
then photon 1 remains in the state described above, meaning that the original polarization of photon 4 is now transmitted onto photon 1.
As a specific example, for FIG. 5(a-a ') (b-b'), where the coordinate m is the topological charge value, Carol is assumed to be at a fixed level, | φ>＝|H>Alice adjusts the applied voltage to produce an integer and a half-integer vortex charge, Q, respectively1′1 and Q1′0.5. When U ═ k_>From equation (14), we can know that the far-end OAM state generated on Bob photons is | φ>1 (1)＝-|Q＝+1>And | phi>1 (2)＝-i|Q＝+0.5>。
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

1. A controllable OAM quantum invisible state transfer system based on W state is characterized by comprising: an Alice terminal and a Bob terminal, wherein the Alice terminal comprises: a hybrid entanglement unit, an entanglement exchange unit, a Path analysis unit, and a SAM analysis unit, the hybrid entanglement unit including: the SAM-OAM mixed entanglement subunit, the SAM-Path mixed entanglement subunit and the SAM-SAM mixed entanglement subunit are connected in series; the Bob end comprises an OAM analysis unit;
the SAM-OAM mixed entanglement subunit comprises a first pumping source, a first prism, a first BBO crystal, a first total reflector and a second total reflector which are sequentially arranged, wherein a first half-wave plate, an OAM generator and a first single-mode fiber are sequentially arranged on the reflection side of the first total reflector;
the pump light generated by the first pump light source passes through the first prism and the first BBO crystal to generate a first orbital angular momentum entangled photon pair, and the first orbital angular momentum entangled photon pair is divided into first signal light and first idle light; the first signal light is output to the OAM analysis unit through the second total reflection mirror; after the first idle light sequentially passes through the first total reflector, the first half-wave plate, the OAM generator and the first single-mode fiber, the first orbital angular momentum entangled photon is converted into a polarization-orbital angular momentum entangled photon pair;
the SAM-Path mixed entanglement subunit comprises a second prism, a second BBO crystal and a fifth total reflector which are arranged in sequence, and a third total reflector and a fourth total reflector which are arranged between the second BBO crystal and the fifth total reflector, wherein a first Q-plate phase plate, a second single-mode fiber and a first lambda/4 wave plate are also arranged on the reflection side of the third total reflector in sequence;
the part of the pump light irradiated on the first BBO crystal transmits through the first BBO crystal to generate a transmitted light beam, the transmitted light beam is reflected to the second BBO crystal again through the fifth total reflector to generate a second orbital angular momentum entangled photon pair, the second orbital angular momentum entangled photon pair is divided into a second signal light and a second idle light, and the second signal light is output to the Path analysis unit through the fourth total reflector; after the second idle light sequentially passes through the third total reflector, the first Q-plate phase plate, the second single-mode fiber and the first lambda/4 wave plate, the second orbital angular momentum entangled photons are converted into polarization-linear momentum entangled photon pairs;
the SAM-SAM hybrid entanglement subunit is used for generating mutually vertical polarization entangled photon pairs, dividing the mutually vertical polarization entangled photon pairs into third signal light and third idle light, sending the third idle light to the entanglement switching unit, and sending the third signal light to the SAM analysis unit;
the entanglement exchanging unit entangles and exchanges the polarization-orbital angular momentum entangled photon pair, the polarization-linear momentum entangled photon pair and the mutually vertical polarization entangled photon pair to obtain multi-degree-of-freedom hybrid entangled W-state photons;
the OAM analysis unit comprises a first spatial light modulator and a third single-photon detector, and the third single-photon detector is used for OAM analysis on the received first signal light;
the Path analysis unit comprises a first computation hologram, two total reflectors and a third beam splitter which are sequentially arranged, the two total reflectors comprise a ninth total reflector and a tenth total reflector, the output end of the third beam splitter is further connected with a fourth single-photon detector and a fifth single-photon detector, and the fourth single-photon detector and the fifth single-photon detector perform Path analysis on the received second signal light; wherein the first computer generated hologram uses an operator of:
Figure FDA0002465224150000021
the SAM analysis unit comprises a third single-mode fiber, a second half-wave plate, a horizontal polarizer and a sixth single-photon detector which are sequentially arranged, and the sixth single-photon detector performs SAM analysis on the received third idle light.
2. The W-state-based controllable OAM quantum invisible state system according to claim 1, wherein:
the OAM generator consists of two conjugated zinc telluride crystal spiral phases, and the transverse crystallization X-Y axis of the zinc telluride crystal has 90-degree relative rotation.
3. The W-state-based controllable OAM quantum invisible state system according to claim 1, wherein:
the Q-plate phase plate is a Pancharatnam-Berry phase plate made of uniaxially birefringent nematic liquid crystal material.
4. The W-state-based controllable OAM quantum invisible state system according to claim 1, wherein:
the SAM-SAM entanglement subunit comprises a second pumping source, a third prism, a first PPKTP crystal, a sixth holophote and a seventh holophote which are arranged in sequence;
and pump light generated by the second pump source passes through the first PPKTP crystal to generate mutually vertical polarization entangled photon pairs, the mutually vertical polarization entangled photon pairs are divided into third signal light and third idle light, the third signal light passes through the seventh holophote and then is output to the SAM analysis unit, and the third idle light passes through the sixth holophote and then enters the entanglement exchange unit after changing the direction.
5. The W-state-based controllable OAM quantum invisible state system according to claim 4, wherein:
the entanglement switching unit comprises an eighth total reflector, a first beam splitter, a second beam splitter and a polarization beam splitter which are sequentially arranged, and the output end of the polarization beam splitter is also connected with a first single-photon detector and a second single-photon detector;
the first idle light output by the first single-mode fiber reaches the first beam splitter after passing through an eighth holophote, the second idle light output by the first lambda/4 wave plate directly reaches the first beam splitter, and the first beam splitter couples each arriving photon and outputs the photon to the second beam splitter; the third idle light output by the sixth total reflection mirror directly reaches the second beam splitter, and the second beam splitter couples each arriving photon and outputs the coupled photon to the polarization beam splitter;
the polarization beam splitter divides photons reaching the polarization beam splitter into horizontal polarization photons and vertical polarization photons, wherein the horizontal polarization photons enter the first single photon detector, and the vertical polarization photons enter the second single photon detector.
6. The W-state-based controllable OAM quantum invisible state system according to claim 1, wherein:
the fifth total reflector is arranged opposite to the second BBO crystal, and an included angle is formed between the third total reflector and the fourth total reflector in space;
the first total reflector and the second total reflector are positioned on the same side of the first BBO crystal, and an included angle is formed in space.
7. The W-state-based controllable OAM quantum invisible state system according to claim 4, wherein:
the sixth total reflector and the seventh total reflector are positioned on the same side of the first PPKTP crystal, and have an included angle in space.
8. A W-state based controllable OAM quantum invisible state transferring method applied to the W-state based controllable OAM quantum invisible state transferring system of any one of claims 1 to 7, comprising the steps of:
s1: respectively generating a polarization-orbital angular momentum entangled photon pair, a polarization-linear momentum entangled photon pair and a mutually vertical polarization entangled photon pair by using an SAM-OAM mixed entanglement subunit, an SAM-Path mixed entanglement subunit and an SAM-SAM mixed entanglement subunit;
s2: respectively transmitting the polarization-orbital angular momentum entangled photon pair, the polarization-linear momentum entangled photon pair and the mutually perpendicular polarization entangled photon pair generated in the step S1 to an entanglement switching unit, and converting the pairs in the entanglement switching unit to obtain multi-degree-of-freedom hybrid entangled W-state photons;
s3: the Alice terminal randomly selects a W state as a quantum channel of the invisible transmission state, performs Bell state measurement according to the selected W state, sends the Bell state measurement result to the Bob terminal through a classical channel, and enters the step S4;
s4: the Bob end carries out local unitary transformation according to the Bell state measurement result;
s5: OAM analysis, Path analysis and SAM analysis are performed by an OAM analysis unit, a Path analysis unit and a SAM analysis unit, respectively.
9. The method of claim 8, wherein the W-state-based controllable OAM quantum invisible state transfer method comprises:
the step S1 includes the steps of:
s1.1: converting a part of pump light sent by a first pump light source into a first orbital angular momentum entangled photon pair through a first prism and a first BBO crystal, forming a transmission beam by a part of the pump light, and dividing the first orbital angular momentum entangled photon pair into first signal light and first idle light;
s1.2: reflecting the first signal light to an OAM analysis unit through a second total reflection mirror; converting the first orbital angular momentum entangled photon into a polarization-orbital angular momentum entangled photon pair sequentially through a first total reflector, a first half-wave plate, an OAM generator and a first single-mode fiber;
s1.3: converting the transmitted beam formed in the step S1.1 into a second orbital angular momentum entangled photon pair through a fifth total reflection mirror and a second BBO crystal, and dividing the second orbital angular momentum entangled photon pair into a second signal light and a second idle light;
s1.4: reflecting the second signal light to a Path analysis unit through a fourth total reflection mirror; and converting the second orbital angular momentum entangled photon into a polarization-linear momentum entangled photon pair sequentially through a third total reflection mirror, a first Q-plate phase plate, a second single-mode fiber and a first lambda/4 wave plate.
10. The method according to claim 8 or 9, wherein the method comprises:
the step S1 further includes the steps of:
s1.1': converting the pump light sent by the second pump source into mutually vertical polarization entangled photon pairs through a third prism and the first PPKTP crystal, and dividing the mutually vertical polarization entangled photon pairs into third signal light and third idle light;
s1.2': the third signal light is reflected to the SAM analysis unit by a seventh total reflection mirror.
CN201811651238.5A 2018-12-31 2018-12-31 W-state-based controllable OAM quantum invisible state transfer system and method Active CN109714110B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201811651238.5A CN109714110B (en) 2018-12-31 2018-12-31 W-state-based controllable OAM quantum invisible state transfer system and method
PCT/CN2019/129506 WO2020140854A1 (en) 2018-12-31 2019-12-27 Quantum teleportation system and method based on controllable oam in w state

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811651238.5A CN109714110B (en) 2018-12-31 2018-12-31 W-state-based controllable OAM quantum invisible state transfer system and method

Publications (2)

Publication Number Publication Date
CN109714110A CN109714110A (en) 2019-05-03
CN109714110B true CN109714110B (en) 2020-11-03

Family

ID=66260642

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811651238.5A Active CN109714110B (en) 2018-12-31 2018-12-31 W-state-based controllable OAM quantum invisible state transfer system and method

Country Status (2)

Country Link
CN (1) CN109714110B (en)
WO (1) WO2020140854A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109714110B (en) * 2018-12-31 2020-11-03 华南师范大学 W-state-based controllable OAM quantum invisible state transfer system and method
CN111147154B (en) * 2019-12-24 2021-03-30 北方工业大学 Multi-unicast network coding method based on quantum repeaters with different dimensions

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104466655A (en) * 2014-12-25 2015-03-25 华南师范大学 Production system and method for polarization-orbital angular momentum mixed entangled state single photon
CN104702342A (en) * 2015-02-10 2015-06-10 华南师范大学 Multi-degree of freedom mixed entangled W-state photon producing system and method

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5434373B2 (en) * 2009-08-26 2014-03-05 沖電気工業株式会社 Quantum entangled photon pair generator
US9754214B1 (en) * 2014-06-27 2017-09-05 Lawrence F. Glaser System for generation of groups of entangled particles for interaction with communication point devices
CN204539149U (en) * 2015-02-10 2015-08-05 华南师范大学 A kind of generation system of multiple degrees of freedom mixing entangled W state photon
CN109714110B (en) * 2018-12-31 2020-11-03 华南师范大学 W-state-based controllable OAM quantum invisible state transfer system and method
CN209517160U (en) * 2018-12-31 2019-10-18 华南师范大学 A kind of quantum teleportation system based on SAM-path-OAM mixing W state

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104466655A (en) * 2014-12-25 2015-03-25 华南师范大学 Production system and method for polarization-orbital angular momentum mixed entangled state single photon
CN104702342A (en) * 2015-02-10 2015-06-10 华南师范大学 Multi-degree of freedom mixed entangled W-state photon producing system and method

Also Published As

Publication number Publication date
WO2020140854A1 (en) 2020-07-09
CN109714110A (en) 2019-05-03

Similar Documents

Publication Publication Date Title
Bogdanov et al. Qutrit state engineering with biphotons
US9270385B2 (en) System and method for quantum based information transfer
Spreeuw Classical wave-optics analogy of quantum-information processing
US8983303B2 (en) Quantum based information transfer system and method
Barz Quantum computing with photons: introduction to the circuit model, the one-way quantum computer, and the fundamental principles of photonic experiments
Liu et al. Experimental remote preparation of arbitrary photon polarization states
CN104702342A (en) Multi-degree of freedom mixed entangled W-state photon producing system and method
US20030086138A1 (en) Techniques for performing logic operations using quantum states of single photons
CN109714110B (en) W-state-based controllable OAM quantum invisible state transfer system and method
CN204539149U (en) A kind of generation system of multiple degrees of freedom mixing entangled W state photon
Wang et al. Practical single-photon-assisted remote state preparation with non-maximally entanglement
EP4035302B1 (en) A system for generating polarisation-entangled photon pairs for repeating a quantum signal over a distance and a method for generating polarisation-entangled photon pairs in a multi-mode quantum memory for repeating a quantum signal over a distance
Ide et al. Continuous-variable teleportation of single-photon states
Schnabel et al. Stokes-operator-squeezed continuous-variable polarization states
Ru et al. Realization of a deterministic quantum Toffoli gate with a single photon
Jiang et al. Efficient and deterministic high-dimensional controlled-swap gates on hybrid linear optical systems with high fidelity
Bacco et al. Quantum communication with orbital angular momentum
Bouchard et al. Measuring ultrafast time-bin qudits
Chen et al. Teleportation of a controllable orbital angular momentum generator
Sephton et al. Stimulated teleportation of high-dimensional information with a nonlinear spatial mode detector
Chen et al. Spin-orbit-path hybrid Greenberger-Horne-Zeilinger entanglement and open-destination teleportation with multiple degrees of freedom
Jen Cascaded cold atomic ensembles in a diamond configuration as a spectrally entangled multiphoton source
Jen et al. Spectral shaping of cascade emissions from multiplexed cold atomic ensembles
CN209517160U (en) A kind of quantum teleportation system based on SAM-path-OAM mixing W state
Hu et al. Path–orbital-angular-momentum high-dimensional hyperentangled photons from a warm atomic ensemble

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20210818

Address after: 510663 room A105, first floor, ladder a, No. 11, panglv Road, Science City, Guangzhou high tech Industrial Development Zone, Guangdong Province

Patentee after: Guangdong Yukopod Technology Development Co.,Ltd.

Address before: School of information and optoelectronics, South China Normal University, 378 Waihuan West Road, Panyu District, Guangzhou, Guangdong 510000

Patentee before: SOUTH CHINA NORMAL University

TR01 Transfer of patent right