CN108415064B - A Polarization System of Diamond Color Core Nuclei - Google Patents

Abstract

The invention discloses a polarization system of a diamond color core nucleus. The system includes an optical control system, a microwave control system, a magnetic field control system, and a control and data acquisition system. Among them, the optical control system, the microwave control system and the magnetic field control system are independent of each other, and are connected with the data acquisition system and related components to form a diamond color core nuclear polarization system. Through the method of laser, microwave, magnetic field, and radio frequency multi-physics acting on diamond according to the design sequence, the interaction between the diamond color center and its surrounding nucleons can be highly sensitively and quickly weakened, which can achieve high nuclear polarization efficiency and improve decoherence for quantum measurement. Time provides support for technologies such as quantum computing, quantum sensing, and quantum transmission based on diamond color centers.

Description

A Polarization System of Diamond Color Core Nuclei

technical field

The invention relates to the technical fields of quantum computing and quantum precision measurement, in particular to a polarization system of diamond color core nuclei.

Background technique

The nuclear polarization of the diamond color center is the basis of quantum precision measurement using the diamond color center. In high-concentration diamond materials, the diamond color center has a chaotic coupling phenomenon with a large number of ¹³ C atoms, NV ₀ , P ₁ and other color centers. Existing diamond color core core spin polarization systems mainly include a color center excited state energy level anti-crossing (ESLAC) polarization system under a strong magnetic field of 500 gauss, a double resonance pole controlled by a microwave radio frequency resonance field and a bias magnetic field. system. The ESLAC polarization system is bulky and expensive, and the nuclear polarizability of the dual resonance system is low.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a polarization system for diamond color core nuclei is provided. The system includes: a diamond sample, an optical manipulation system, a microwave manipulation system, a magnetic field manipulation system, and a control and data acquisition system. in,

The diamond sample is processed by a special process and fixed on the platform by a fixing device;

The optical manipulation system takes the diamond sample as the core, is arranged before and after the sample, introduces the modulated laser into the sample and collects the fluorescent signal generated after interacting with the sample;

The microwave control system takes the diamond sample as the core and is arranged on both sides of the sample, and the modulated microwave signal is introduced into the diamond sample. The microwave control system and the optical control system are independent of each other and do not affect each other;

The magnetic field manipulation system includes the diamond sample in the central area of the device, and some components of the optical manipulation system and the microwave manipulation system are included in the magnetic field manipulation system;

The control and data acquisition system is connected to the optical control system and the microwave control system, and controls the operations between the systems and derives data results.

Among them, the optical control system includes: (1) a diamond color center electronic polarization optical path system, the main components of the optical path system are a laser source, a beam modulation device and corresponding optical components, wherein each component is connected by a spatial optical path, and the light beam The modulation device is connected to the control and data acquisition system, and the optical circuit system is mainly used to complete the polarization of the electron quantum state of the diamond color center; (2) the coherent layout of the diamond color center traps the nuclear spin decoupling optical circuit system, and the optical circuit system mainly The components are a laser source, a beam modulation device and corresponding optical components, wherein each component is connected by a spatial optical path, and the beam modulation device is connected with the control and data acquisition system. The main function of the optical path system is to generate accurate alignment. The ultrafine energy level transition of the diamond color center realizes coherent population and trapping to complete the decoupling of the color center and surrounding nucleons; (3) the optical path system for fluorescence collection and detection, the main components of the optical path system are detectors, optical path regulators and related components, Among them, each component is connected by a spatial optical path, and the detector is connected with the control and data acquisition system. The optical path system is mainly used to collect and detect photon sideband fluorescence and zero-phonon line detection of diamond color center fluorescence, and track Observation of the spin polarization of the diamond color core.

The microwave control system includes: a microwave source, a switch, an amplifier, a transmission antenna and a load. The microwave source and the switch are connected to the control and data acquisition system. The system is used to generate and control the flipping of diamond color center electrons between ground state quantum states. microwave pulse sequence.

Among them, the magnetic field control system includes: a power supply and a magnetic field generating device. The system controls the magnetic field generating device by regulating the power supply to generate a precise current, thereby generating a stable magnetic field that makes the diamond color center electrons generate Zeeman splitting.

Among them, the control and data acquisition system includes the design sequence to carry out joint adjustment of the above three control systems, system feedback control and data acquisition and processing.

The advantages of the present invention compared with the prior art are:

Through the multi-physics of laser, microwave and magnetic field acting on the diamond sample according to the design sequence, the interaction between the diamond color center and its surrounding nucleons is highly sensitively and rapidly weakened. It can reduce the uniform broadening of the diamond color center and reduce the coupling of the ¹⁴ N nuclear spin ensemble of the diamond color center and the cluttered environment, so that the ^hyperfine energy level is clearer. Spin ensemble polarization. The system has fast reaction rate, simple experimental environment and good robustness. The system can not only provide the high precision of hyperfine energy level that is easy to align for the stable polarization state, but also prolong the ^decoherence time of the diamond color center to a certain extent. The process provides time guarantee. In the experiment of using the diamond color center for quantum precision measurement, the decoherence time for quantum measurement can be effectively improved, thereby improving the sensitivity of quantum measurement based on diamond color center.

Description of drawings

1 is a schematic diagram of the basic structure of a diamond color core nuclear polarization system provided by an embodiment of the present invention;

2 is a schematic diagram of a diamond color center electron polarization optical path system in an optical manipulation system provided by an embodiment of the present invention;

3 is a schematic diagram of a decoupling optical path system of a diamond color center coherent layout trapped nuclear spin in an optical manipulation system provided by an embodiment of the present invention;

4 is a schematic diagram of a fluorescence collection and detection optical path system in an optical manipulation system provided by an embodiment of the present invention;

5 is a schematic diagram of a microwave control system provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of a polarization system of a diamond color core nucleus according to an embodiment of the present invention.

Detailed ways

In order to express the technical solutions and advantages of the embodiments of the present invention more clearly, the technical solutions of the present invention are further described in detail below through the accompanying drawings and embodiments.

1 is a schematic diagram of the basic structure of a diamond color core nuclear polarization system provided by an embodiment of the present invention. The necessary technical core of the system includes: a diamond sample 101, an optical control system 105, a microwave control system 104, and a magnetic field control system 103. Control and data acquisition system 102 . in,

The diamond sample 101 is processed by a special process, and is fixed on the platform by a fixing device;

The optical manipulation system 105 takes the diamond sample as the core, is arranged before and after the sample, introduces the modulated laser light into the sample and collects the fluorescent signal generated after interacting with the sample;

The microwave control system 104 takes the diamond sample as the core, is arranged on both sides of the sample, and introduces the modulated microwave signal into the diamond sample. The microwave control system and the optical control system are independent of each other and do not affect each other;

The magnetic field manipulation system 103 includes the diamond sample in the central area of the device, and some components of the optical manipulation system and the microwave manipulation system are included in the magnetic field manipulation system;

The control and data acquisition system 102 is connected to the optical control system and the microwave control system, and controls the operations between the systems and derives data results.

The control and data acquisition system controls the optical control system, the microwave control system, and the magnetic field control system by designing the timing sequence, so that the system operates according to the above method, and generates a mixed pulse sequence of laser, microwave and magnetic field to act on the diamond sample, with high sensitivity and fast response speed. The interaction between the diamond color center and its surrounding nucleons is weakened to achieve nuclear polarization. Increase the decoherence time for quantum measurements, thereby improving the sensitivity of quantum measurements based on diamond color centers.

The necessary technical core of the optical manipulation system includes a diamond color center polarization system, a diamond color center coherent layout trapped nuclear spin decoupling optical path system, and a fluorescence collection and detection optical path system. The main features of the optical manipulation system are: complete the polarization preparation of the diamond color center, complete the decoupling of the color center and the nucleus and the collection and detection of the fluorescence signal under the cooperation of the microwave and magnetic field manipulation system. Next, for the convenience of explanation, the composition and function of each subsystem will be explained.

The main components of the diamond color center polarization system are the laser source, the beam modulation device and the corresponding optical components. Each component is connected by a spatial optical path, and the beam modulation device is connected with the control and data acquisition system. The main function of the optical path system is as follows: Complete the electron quantum state polarization of the diamond color center. 2 is a schematic diagram of a diamond color center polarized optical path system in an optical manipulation system provided by an embodiment of the present invention. For example, the laser light generated by the laser 201 is passed through the isolator 202, the first acousto-optic modulator 203, the first two The chromatic mirror 204 and the modulating wave plate 205 adjust the optical path characteristics, and then focus on the diamond sample through the confocal objective lens 206, and use the special energy level characteristics of the diamond color center to prepare it into a special quantum state. Among them, the first acousto-optic modulation Controller 203 is controlled by control and data acquisition system 102 . The reflection lens 207 of the diamond color center polarization optical path system reflects the fluorescence emitted by the diamond sample 101, and guides the fluorescence into the fluorescence collection and detection optical path system.

As an option, the main components of the decoupling optical circuit system of the trapped nuclear spin in the coherent layout of the diamond color center are the laser source, the beam modulation device and the corresponding optical components. Connected with the data acquisition system, the main function of the optical path system is to generate hyperfine energy level transitions precisely aligned with the diamond color center, realize coherent population and trap, and complete the decoupling of the color center and surrounding nucleons. 3 is a schematic diagram of an optically manipulated diamond color center coherent layout trapped nuclear spin decoupling optical circuit system provided by an embodiment of the present invention. Two tunable lasers are used, namely the second tunable laser 301 and the third tunable laser 305. After the second tunable laser 301 passes through the second isolator 302, the second acousto-optic modulator 303 and the frequency locker 304 are used to The frequency of the second tunable laser 301 is strictly locked between the two energy levels corresponding to the color center. The laser light emitted by the third tunable laser 305 passes through the third isolator 306 , then passes through the third acousto-optic modulator 307 , the first waveguide modulator 308 , and the second waveguide modulator 309 , and then emits with the second tunable laser 301 After the first polarization beam splitting prism 310 converges, the laser beams enter the first detector 311 for frequency exclusion, and then the frequency of the third tunable laser 305 is precisely controlled by the feedback differential circuit 312 . The two modulated laser beams will act on the diamond sample 101 through the polarization beam splitter prism 402 to decouple the color center and the nucleons. The second acousto-optic modulator 303 , the third acousto-optic modulator 307 , the first waveguide modulator 308 , the second waveguide modulator 309 and the first detector 311 are all connected to the control and data acquisition system 102 .

As an option, the main components of the optical path system for fluorescence collection and detection are detectors, optical path regulators and related components. Each component is connected by a spatial optical path, and the detector is connected with the control and data acquisition system. The optical path system is mainly The function is to perform photon sideband fluorescence collection detection and zero-phonon line detection on the diamond color center fluorescence, and track and observe the state of the spin polarization of the diamond color center core. FIG. 4 is a schematic diagram of an optical path system for optically manipulated fluorescence collection and detection provided by an embodiment of the present invention. The returned fluorescence of the diamond sample 101 passes through the first dichroic mirror 204 to filter the laser for depolarization, and then passes through the second dichroic mirror 401 to separate the light beam, and the reflected part of the fluorescence enters the second detector 406 for edge detection. With fluorescence detection; the penetrating fluorescence first passes through the second beam splitting prism 402 in the reverse direction, and then passes through the polarization detection device 403 composed of a modulation wave plate and a third offset beam splitting prism 403 for polarization detection, and after being modulated by the beam conditioner 404, Then enter the third detector 405 for zero-phonon line detection. The sideband fluorescence detection signal and the zero-phonon ray detection signal are subjected to differential processing by the differential device 407, and the obtained differential signal is input to the analyzer 408 for signal analysis to detect the polarization of the diamond color core nucleus. Among them, the analyzer 408 is connected to the control and data acquisition system 102 .

As an option, the necessary components of the microwave control system include: microwave source, switch, amplifier, transmission antenna and load. The microwave source is connected with the switch control and data acquisition system. The system is used to generate a microwave pulse sequence that controls the flipping of diamond color center electrons between ground state quantum states, and realizes quantum state manipulation between diamond color center energy levels. 5 is a schematic diagram of a microwave control method provided by an embodiment of the present invention; the microwave source 501 generates a microwave signal under the operation of the control and data acquisition system 102, and then the control and data acquisition system 102 controls the microwave switch 502 to open and intercept the microwave source. The microwave formed pulse sequence, after passing through the amplifier 503, acts on the diamond sample 101 through the microwave antenna, and finally the microwave ends at the load 504. Different microwave sequences can be formed by designing the timing control switch state to improve the quantum state manipulation effect.

As an option, the magnetic field manipulation system includes the diamond sample 101 in the central region of the device, and some components of the optical manipulation system and the microwave manipulation system are included in the magnetic field manipulation system. The necessary components of the magnetic field manipulation system are the magnetic field generator and the current source. The necessary technical core of the magnetic field manipulation method includes precise manipulation of the magnitude and direction of the magnetic field. Its main feature is: to provide necessary magnetic field environmental conditions for the nuclear polarization around the diamond color center. For example, as shown in FIG. 6 , the size and direction of the magnetic field are precisely controlled by using a three-axis Helm-Hertz coil 103 through a current.

As an option, the necessary technical core of the control and data acquisition system includes designing the timing sequence to carry out joint adjustment of the above three control systems, system feedback control and data acquisition and processing. Its main features are: providing timing signals to control the above-mentioned laser, microwave and magnetic field systems to complete nuclear polarization, collecting data and analyzing. For example, as shown in FIG. 6 , the control and data acquisition system 102 generates the design timing to control the first acousto-optic modulator 202 in the diamond color center polarization system; The second acousto-optic modulator, the third acousto-optic modulator, the first waveguide modulator 308, the second waveguide modulator 309; the microwave source 501 and the microwave switch 502 in the microwave control system; and the first detector 311, the second The signal data of the detector 406 and the third detector 405 are analyzed.

FIG. 6 is a schematic diagram of a polarization system of a diamond color core nucleus according to an embodiment of the present invention. The polarization system includes the system described in Figures 2-5 and the magnetic field manipulation system. Among them, the optical, microwave and magnetic field control systems are independent of each other, and the diamond color core nuclear polarization system is formed through the connection of the control and data acquisition system and related components. Through the multi-physical fields of laser, microwave and magnetic field acting on the diamond according to the design sequence, the interaction between the diamond color center and its surrounding nucleons is weakened with high sensitivity and fast reaction speed, the nuclear polarization is realized, and the decoherence time for quantum measurement is improved. The sensitivity of quantum measurement of diamond color centers increases the types of detection methods.

The parts of the present invention that are not disclosed in detail belong to the well-known technology in the art.

Although the illustrative specific embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, As long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the inventive concept are included in the protection list.

Claims (4)

1. A polarization system of diamond color center nuclei, characterized in that: the system comprises: diamond sample, optical control system, microwave control system, magnetic field control system, control and data acquisition system, wherein:

the diamond sample is fixed on the platform by a fixing device;

the optical control system takes a diamond sample as a core, is arranged in front of and behind the sample, guides modulated laser into the sample and collects a fluorescence signal generated after the interaction with the sample;

the microwave control system takes a diamond sample as a core, is arranged on two sides of the sample, and guides a modulated microwave signal into the diamond sample, and the microwave control system and the optical control system are independent and do not influence each other;

the magnetic field control system contains the diamond sample in the central area of the device, and the optical control system and part of the microwave control system are contained in the magnetic field control system;

the control and data acquisition system is connected with the optical control system and the microwave control system, so that the operation among the systems is uniformly regulated and controlled and data results are exported;

wherein, the optical control system includes: (1) the diamond color center electronic polarization optical path system mainly comprises a laser source, an isolator, an acousto-optic modulator, a dichroic mirror, a modulation wave plate, a co-focusing objective lens and a reflection lens, wherein all the components are connected through a spatial optical path; (2) the diamond color center coherent population trapping nuclear spin decoupling optical path system mainly comprises 2 tunable lasers, an isolator, an acousto-optic modulator, a frequency locker, a polarization beam splitter prism, a waveguide modulator and a feedback differential circuit, wherein all the components are connected through a spatial optical path, the acousto-optic modulator and the waveguide modulator of a light beam modulator are connected with the control and data acquisition system, and the optical path system mainly acts on generating hyperfine energy level transition which is accurately aligned with the diamond color center to realize coherent population trapping to finish the decoupling of the color center and surrounding nuclei; (3) the fluorescence collection detection optical path system mainly comprises a detector, a modulation wave plate, a bias beam splitter prism, a dichroic mirror, a light beam regulator, a difference device and an analyzer, wherein all the components are connected through a spatial optical path, the analyzer is connected with the control and data acquisition system, and the optical path system is mainly used for carrying out photon sideband fluorescence collection detection and zero phonon line detection on diamond color center fluorescence and tracking and observing the spin polarization condition of diamond color center nuclei.

2. A polarization system for diamond color center nuclei according to claim 1, wherein: the microwave control system comprises: the system comprises a microwave source, a switch, an amplifier, a transmission antenna and a load, wherein the microwave source and the switch are connected with the control and data acquisition system, and the system is used for generating a microwave pulse sequence for controlling the diamond color center electrons to overturn between the ground state quantum states.

3. A polarization system for diamond color center nuclei according to claim 1, wherein: the magnetic field manipulation system comprises: the system controls the magnetic field generating device by regulating and controlling the power supply to generate accurate current, and further generates a stable magnetic field which enables diamond color center electrons to generate Zeeman splitting.

4. A polarization system for diamond color center nuclei according to claim 1, wherein: the control and data acquisition system comprises a design time sequence for joint debugging, system feedback regulation and control and data acquisition processing of the three control systems.

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