CN117521824A - Quantum bit control signal adjusting method and device and quantum computer - Google Patents
Quantum bit control signal adjusting method and device and quantum computer Download PDFInfo
- Publication number
- CN117521824A CN117521824A CN202210915172.6A CN202210915172A CN117521824A CN 117521824 A CN117521824 A CN 117521824A CN 202210915172 A CN202210915172 A CN 202210915172A CN 117521824 A CN117521824 A CN 117521824A
- Authority
- CN
- China
- Prior art keywords
- control signal
- quantum
- experimental data
- qubit
- detuning
- 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.)
- Pending
Links
- 239000002096 quantum dot Substances 0.000 title claims abstract description 152
- 238000000034 method Methods 0.000 title claims abstract description 33
- 238000002474 experimental method Methods 0.000 claims abstract description 21
- 230000008859 change Effects 0.000 claims abstract description 17
- 238000004590 computer program Methods 0.000 claims description 4
- 230000003750 conditioning effect Effects 0.000 claims 2
- 230000000694 effects Effects 0.000 abstract description 7
- 230000005699 Stark effect Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 9
- 230000007704 transition Effects 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 230000005283 ground state Effects 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000005040 ion trap Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000005610 quantum mechanics Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06N—COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
- G06N10/00—Quantum computing, i.e. information processing based on quantum-mechanical phenomena
- G06N10/20—Models of quantum computing, e.g. quantum circuits or universal quantum computers
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06N—COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
- G06N10/00—Quantum computing, i.e. information processing based on quantum-mechanical phenomena
- G06N10/40—Physical realisations or architectures of quantum processors or components for manipulating qubits, e.g. qubit coupling or qubit control
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06N—COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
- G06N10/00—Quantum computing, i.e. information processing based on quantum-mechanical phenomena
- G06N10/60—Quantum algorithms, e.g. based on quantum optimisation, quantum Fourier or Hadamard transforms
Landscapes
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mathematical Analysis (AREA)
- Data Mining & Analysis (AREA)
- Evolutionary Computation (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Computational Mathematics (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Computing Systems (AREA)
- General Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Software Systems (AREA)
- Artificial Intelligence (AREA)
- Superconductor Devices And Manufacturing Methods Thereof (AREA)
Abstract
The invention provides a method for adjusting a qubit control signal, which comprises the following steps: acquiring a physical model, wherein the physical model is used for acquiring theoretical expectation of the change of quantum state information of a quantum bit along with the tuning-off quantity, and the tuning-off quantity is the quantity of the frequency deviation bit frequency of the quantum bit control signal; performing an APE experiment on the quantum bit to obtain experimental data, wherein the experimental data comprises a corresponding relation between quantum state information and detuning amount of the quantum bit; judging whether the experimental data meets the requirements or not based on a physical model and the experimental data; the qubit control signal is adjusted based on the experimental data meeting requirements. The technical scheme of the application adjusts the quantum bit control signal to have a detuning quantity which is used for counteracting the working frequency offset caused by the ACStark effect, so that the fidelity of the logic gate operation can be kept at a higher level.
Description
Technical Field
The invention belongs to the technical field of quantum measurement and control, and particularly relates to a method and a device for adjusting a quantum bit control signal and a quantum computer.
Background
Quantum computation and quantum information are a cross subject for realizing computation and information processing tasks based on the principle of quantum mechanics, and have very close connection with subjects such as quantum physics, computer science, informatics and the like. Since quantum computing has a potential to solve specific problems far beyond the development of classical computer performance, in order to realize a quantum computer, it is necessary to obtain a quantum chip containing a sufficient number and a sufficient mass of qubits, and to enable quantum logic gate operation and reading of the qubits with extremely high fidelity.
In the process of testing a quantum chip, each parameter of each quantum bit in the quantum chip needs to be tested and characterized, a series of control signals need to be applied to the quantum bit through an XY line, the control signals applied by the XY line can induce an AC Stark effect between a |1> state and a |2> state, the effect can push away the |1> state and the |2> state, the transition frequency from the |0> state to the |1> state is slightly changed, the fidelity of the operation of a logic gate is reduced, and a harmonic loss is needed to be given to the control signals to offset the effect.
Therefore, it is necessary to provide a method for adjusting the qubit control signal to solve the problem that the control signal in the prior art may cause the reduction of the fidelity of the logic gate operation.
It should be noted that the information disclosed in the background section of the present application is only for enhancement of understanding of the general background of the present application and should not be taken as an admission or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
Disclosure of Invention
The invention aims to provide a method and a device for adjusting a quantum bit control signal and a quantum computer, which are used for solving the problem that the fidelity of logic gate operation is reduced due to the AC Stark effect caused by the quantum bit control signal in the prior art.
To achieve the above object, in a first aspect, the present invention provides a method for adjusting a qubit control signal, including:
acquiring a physical model, wherein the physical model is used for acquiring theoretical expectation of the change of quantum state information of a quantum bit along with the tuning-off quantity, and the tuning-off quantity is the quantity of the frequency deviation bit frequency of the quantum bit control signal;
performing an APE experiment on the quantum bit to obtain experimental data, wherein the experimental data comprises a corresponding relation between quantum state information and detuning amount of the quantum bit;
judging whether the experimental data meets the requirements or not based on a physical model and the experimental data;
the qubit control signal is adjusted based on the experimental data meeting requirements.
Preferably, the physical model includes:
the change relation of the quantum state information along with the tuning quantity satisfies the following conditions:
y＝Acos[2πf 0 (x-Φ)]+C
wherein y is quantum state information, x is detuning amount, A, f 0 And C and phi are parameters of the physical model.
Preferably, the performing an APE experiment on the qubit to obtain experimental data, where the experimental data includes a correspondence between quantum state information of the qubit and a detuning amount, and the method includes:
acquiring N pairs of quantum bit control signals, wherein any pair of the quantum bit control signals is used for enabling quantum state information of the quantum bit to change from a first quantum state to a second quantum state and from the second quantum state to the first quantum state;
determining a first scanning interval and a first scanning step length of the detuning quantity, updating the frequency of the N pairs of quantum bit control signals according to the first scanning interval and the first scanning step length, and applying the updated N pairs of quantum bit control signals to the quantum bits to obtain first data of the quantum state information changing along with the detuning quantity after the current N pairs of quantum bit control signals act;
at least two sets of first data are acquired.
Preferably, the determining whether the experimental result meets the requirement based on the physical model and the experimental result includes:
and judging whether the experimental result meets the requirements or not by using the fitting goodness of the physical model and the experimental data.
Preferably, the determining whether the experimental result meets the requirement by using the goodness of fit to the physical model and the experimental data includes:
constructing a first formula, wherein the first formula is as follows:
wherein R is 2 To the extent of fitting, y fit In order to obtain theoretical expectation according to the physical model, y raw In order to make the data of the experiment,is the average of the experimental data;
and comparing the fitting degree with a first preset threshold value by using the first formula, and judging whether the experimental data meets the requirement.
Preferably, the comparing the fitting degree obtained by using the first formula with a first preset threshold value, and judging whether the experimental data meets the requirement includes:
judging the R 2 Whether the first preset threshold value is larger than the first preset threshold value;
if yes, judging that the experimental result meets the requirement;
if not, judging that the experimental result is not in accordance with the requirement.
Preferably, said adjusting said qubit control signal based on said experimental data meeting requirements comprises:
acquiring at least two groups of first data meeting the requirements;
respectively obtaining detuning amounts corresponding to the quantum state information in the maximum value points in the first data;
obtaining at least two closest or equal detuning amounts in the detuning amounts corresponding to the maximum value point;
judging whether the closest or equal at least two detuning amounts meet the requirement or not based on the maximum value and the minimum value of the closest or equal at least two detuning amounts;
if so, adjusting the qubit control signal based on the at least two detunes.
Preferably, the determining whether the at least two closest or equal detuning amounts meet a requirement includes:
obtaining the difference value between the maximum value and the minimum value in the closest or equal at least two tuning amounts;
judging whether the absolute value of the difference value is not larger than a second preset threshold value or not;
if yes, judging that the obtained at least two detuning amounts meet the requirements.
Preferably, said adjusting said qubit control signal based on said at least two detunes comprises:
and adjusting the frequency of the qubit control signal by taking the average value of the at least two detuning amounts as the detuning amount.
In a second aspect, the present application provides an adjusting device for a qubit control signal, including:
a physical model acquisition module configured to acquire a physical model for acquiring a theoretical expectation of a change in quantum state information of a qubit with a mismatch amount, the mismatch amount being an amount by which a frequency of the qubit control signal deviates from a bit frequency;
an experimental data acquisition module configured to perform an APE experiment on the qubit to acquire experimental data including a correspondence of quantum state information of the qubit and a detuning amount;
a judging module configured to judge whether the experimental data meets a requirement based on a physical model and the experimental data;
an adjustment module configured to adjust the qubit control signal based on the experimental data as required.
In a third aspect, the present application provides a readable storage medium having stored thereon a computer program which, when executed, enables the method of adjusting a qubit control signal provided in the first aspect of the present application.
In a fourth aspect, the present application provides a quantum computer comprising the adjustment device of the qubit control signal provided in the second aspect of the present application.
Compared with the prior art, the method has the following beneficial effects:
according to the adjusting method for the qubit control, whether experimental data of the change of the quantum state information along with the mismatch quantity obtained by an APE experiment meets the requirements is judged through a physical model, the experimental data meeting the requirements is further obtained, the mismatch quantity for adjusting the control information is obtained based on the experimental data, the influence of the control signal on the operation fidelity of the logic gate is reduced to the minimum, and the operation fidelity of the logic gate is improved.
The adjusting device, the quantum computer and the readable storage medium of the quantum bit control signal provided by the application belong to the same conception as the adjusting method of the quantum bit control signal provided by the application, have the same beneficial effects and are not described in detail herein.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flow chart of a method for adjusting a qubit control signal according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a qubit energy level system affected by the AC Stark effect according to one embodiment of the present application;
FIG. 3 is a schematic diagram of quantum state information according to an embodiment of the present application as a function of the amount of tuning;
FIG. 4 is a schematic diagram of quantum state information according to an embodiment of the present application as a function of the amount of tuning away;
FIG. 5 is a schematic diagram showing multiple sets of first data in the same coordinate system according to an embodiment of the present application;
fig. 6 is a schematic structural diagram of an adjusting device for a qubit control signal according to an embodiment of the present application.
Detailed Description
Specific embodiments of the present invention will be described in more detail below with reference to the drawings. Advantages and features of the invention will become more apparent from the following description and from the claims. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.
In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
An embodiment of the present application provides a method for adjusting a qubit control signal, referring to fig. 1, fig. 1 is a flow chart of the method for adjusting a qubit control signal provided in an embodiment of the present application; as can be seen from the figure, the adjustment method comprises the following steps:
s1, acquiring a physical model, wherein the physical model is used for acquiring theoretical expectation of the change of quantum state information of a quantum bit along with the tuning-off quantity, and the tuning-off quantity is the quantity of the frequency deviation bit frequency of a quantum bit control signal;
s2, performing an APE experiment on the quantum bit to obtain experimental data, wherein the experimental data comprises a corresponding relation between quantum state information and detuning amount of the quantum bit;
s3, judging whether the experimental data meets the requirements or not based on a physical model and the experimental data;
and S4, adjusting the quantum bit control signal based on the experimental data meeting the requirements.
According to the adjusting method of the quantum bit control signal, firstly, a physical model is obtained, wherein the physical model is used for obtaining theoretical expectation that quantum state information of a quantum bit changes along with a tuning quantity, and the quantum state information comprises probability that the quantum bit is in a ground state or probability that the quantum bit is in an excited state; then, performing an APE experiment on the quantum bit to obtain experimental data, wherein the experimental data comprises the corresponding relation between quantum state information and detuning amount of the quantum bit; judging whether the experimental data meets the requirements or not based on the physical model and the experimental data; and finally, adjusting the qubit control signal based on the experimental data meeting the requirements. According to the method for adjusting the qubit control signal, experimental data are obtained through APE experiments, theoretical expectations of experimental results are obtained through a physical model, whether the experimental data meet requirements or not is judged, finally, the qubit control signal is adjusted based on the obtained experimental data meeting the requirements, the adjusted control signal has a detuning amount, the detuning amount is used for counteracting working frequency offset caused by an AC Stark effect, and the fidelity of the control signal with the detuning amount can be kept at a higher level.
In the step S1, the physical model is configured to obtain theoretical expectation that quantum state information of a qubit changes along with a tuning amount, and in this embodiment, the qubit may be a resonant system formed based on an inductance element of a superconducting josephson junction and a capacitance to ground and having multiple energy levels, where any two energy levels of the resonant system have corresponding transition frequencies, and the transition frequencies may be regulated by an externally applied magnetic flux modulation signal. In addition, in other embodiments, semiconductor qubits, ion trap qubits, or qubits of other structures may also be selected. After the preparation of the circuit structure of the quantum bit on the superconducting quantum chip is finished, the natural frequency parameter of the circuit structure is determined, but when the quantum bit works, not only the natural frequency point can be selected as the working frequency point, but also other frequency points can be selected as the working frequency point, namely, the working frequency point of the quantum bit can be changed by applying a specific magnetic flux modulation signal.
The qubit control signal is a microwave driving signal for providing transition energy for an energy level system of the qubit, namely, regulating and controlling the quantum state of the qubit. The microwave driving signal realizes quantum state regulation and control through microwave resonance with an energy level system, and the difference between the frequency of the microwave driving signal and the working frequency of the quantum bit can directly influence the effect of microwave resonance, thereby influencing the effect of quantum state regulation and control.
As described in the background art, when a microwave driving signal is applied to a qubit, a transition frequency is slightly changed due to an AC Stark effect, referring to fig. 2, fig. 2 is a schematic diagram of an energy level system of the qubit affected by the AC Stark effect, and as can be seen from fig. 2, a transition frequency from an i 0> state to an i 1> state is slightly changed, so that an effect of microwave resonance is affected, a regulation effect on the qubit state is reduced, and a fidelity of a quantum logic gate operation is reduced, so that in order to solve the problem, a frequency of the microwave driving signal needs to have a detuning amount, that is, a difference between a frequency of a qubit control signal (microwave driving signal) and the qubit frequency. The present embodiment provides a method for adjusting a qubit control signal, which is used for solving the problems mentioned in the background art.
In the step S1, the theoretical expectation of the variation of the qubit information with the amount of mismatch includes a theoretical expectation of the variation of the probability of the qubit in the state |0> with the amount of mismatch or a theoretical expectation of the variation of the probability of the qubit in the state |1> with the amount of mismatch.
The physical model specifically comprises: the change relation of the quantum state information along with the tuning quantity satisfies the following conditions:
y＝Acos[2πf 0 (x-Φ)]+C
wherein y is quantum state information, x is detuning amount, A, f 0 And C and phi are parameters of the physical model.
Based on the physical model, theoretical expectations of the quantum state information changing with the amount of mismatch can be obtained.
In the step S2, the performing an APE experiment on the qubit to obtain experimental data, where the experimental data includes a correspondence between quantum state information of the qubit and a mismatch amount, and specifically includes:
acquiring N pairs of quantum bit control signals, wherein any pair of the quantum bit control signals is used for enabling quantum state information of the quantum bit to change from a first quantum state to a second quantum state and from the second quantum state to the first quantum state;
determining a first scanning interval and a first scanning step length of the detuning quantity, updating the frequency of the N pairs of quantum bit control signals according to the first scanning interval and the first scanning step length, and applying the updated N pairs of quantum bit control signals to the quantum bits to obtain first data of the quantum state information changing along with the detuning quantity after the current N pairs of quantum bit control signals act;
at least two sets of first data are acquired.
According to the embodiment, at least two groups of first data are obtained based on specific steps of an APE experiment, the first data reflect the corresponding relation between quantum state information of the quantum bit subjected to the action of the N pairs of control signals and the detuning amount, and the corresponding relation between the probability of the quantum bit in the state of |0> and the detuning amount can be obtained, and the corresponding relation between the probability of the quantum bit in the state of |1> and the detuning amount can be obtained.
Referring to fig. 3, fig. 3 is a schematic diagram illustrating a change of quantum state information according to a tuning amount according to an embodiment of the present application; the ordinate is probability that the quantum bit is in the state of |0>, the transverse axis is detuning quantity, the unit of the transverse axis is GHz, the curve A is the corresponding relation between quantum state information obtained by an APE experiment and the detuning quantity, and the curve B is theoretical expectation that the quantum state information obtained by a physical model changes along with the detuning quantity. Referring to fig. 4, fig. 4 is a schematic diagram illustrating a change of quantum state information according to a tuning amount according to an embodiment of the present application; the ordinate is probability that the quantum bit is in the |1> state, the abscissa is the detuning amount, the curve C is the corresponding relation between quantum state information obtained by an APE experiment and the detuning amount, and the curve D is theoretical expectation that the quantum state information obtained by a physical model changes along with the detuning amount.
Specifically, the first data alone, although being capable of acquiring the variation relationship of quantum state information with the amount of detuning, cannot determine a specific position capable of canceling the amount of detuning of the operating frequency offset due to the AC Stark effect. Therefore, at least two sets of the first data are required.
The use of N pairs of qubit control signals causes errors in the qubit control signals to accumulate, see fig. 3 and 4. The corresponding relation between the quantum state information and the tuning-out quantity satisfies the cosine function relation, and the oscillation frequency is related to the logarithm N of the quantum bit control signal, wherein the larger the value of N is, the larger the oscillation frequency is.
In the step S3, the step of determining whether the experimental result meets the requirement based on the physical model and the experimental result includes:
and judging whether the experimental result meets the requirements or not by using the fitting goodness of the physical model and the experimental data.
Judging whether the experimental result is required or not through the fitting goodness, discarding the experimental data with poor experimental result in the APE experiment, and adjusting the qubit control signal based on the experimental data meeting the requirements.
Specifically, judging whether the experimental result meets the requirements by using the goodness of fit comprises:
constructing a first formula, wherein the first formula is as follows:
wherein R is 2 To the extent of fitting, y fit In order to obtain theoretical expectation according to the physical model, y raw In order to make the data of the experiment,is the average of the experimental data;
and comparing the fitting degree with a first preset threshold value by using the first formula, and judging whether the experimental data meets the requirement.
Specifically, the step of obtaining the fitting degree by using the first formula and comparing the fitting degree with a first preset threshold value, and the step of judging whether the experimental data meets the requirement includes:
judging the R 2 Whether the first preset threshold value is larger than the first preset threshold value;
if yes, judging that the experimental result meets the requirement;
if not, judging that the experimental result is not in accordance with the requirement.
In this embodiment, by setting the preset threshold to 0.8, in other embodiments, the first preset threshold may also be set to 0.75, 0.85 or 0.9, and the corresponding setting may be performed according to the required operation precision.
Additionally, in the step S4, the adjusting the qubit control signal based on the experimental data meeting the requirements includes:
acquiring at least two sets of first data meeting requirements for determining specific positions capable of counteracting the detuning amount of the working frequency offset caused by the AC Stark effect; in addition, in the two groups of first data, the value of N should be different;
respectively obtaining detuning amounts corresponding to the quantum state information in the maximum value points in the first data;
obtaining at least two closest or equal detuning amounts in the detuning amounts corresponding to the maximum value point;
judging whether the closest or equal at least two detuning amounts meet the requirement or not based on the maximum value and the minimum value of the closest or equal at least two detuning amounts; obtaining the difference value between the maximum value and the minimum value in the closest or equal at least two tuning amounts; judging whether the absolute value of the difference value is not larger than a second preset threshold value or not; in this embodiment, the second preset threshold is 0.2MHz, and in other embodiments, the second preset threshold with other values may be selected, and the selection may be performed according to the required test precision.
If yes, determining that the obtained at least two detuning amounts meet requirements and adjusting the qubit control signal based on the at least two detuning amounts, specifically including: and adjusting the frequency of the qubit control signal by taking the average value of the at least two detuning amounts as the detuning amount.
Referring to fig. 5, fig. 5 is a schematic diagram showing a plurality of sets of first data in the same coordinate system in an embodiment of the present application, where the ordinate is probability that a qubit is in a state of |0>, the abscissa is a detuning amount (in GHz), and when the N values are 9, 13, and 15 respectively, the first data obtained when the N values are respectively shown in the same coordinate system, and the detuning amounts of the maximum points of the three sets of first data corresponding to the arrow points in the figure are almost equal, which indicates that the detuning amount corresponding to the position can offset the working frequency offset caused by the AC Stark effect, and further adjusts the qubit control signal by an average value of three detuning amounts corresponding to the position in fig. 5, where the average value of the three detuning amounts is-0.003 GHz.
In summary, the present application provides a method for adjusting a qubit control signal, including: acquiring a physical model, wherein the physical model is used for acquiring theoretical expectation of the change of quantum state information of a quantum bit along with the tuning-off quantity, and the tuning-off quantity is the quantity of the frequency deviation bit frequency of the quantum bit control signal; performing an APE experiment on the quantum bit to obtain experimental data, wherein the experimental data comprises a corresponding relation between quantum state information and detuning amount of the quantum bit; judging whether the experimental data meets the requirements or not based on a physical model and the experimental data; the qubit control signal is adjusted based on the experimental data meeting requirements. The technical scheme of the method and the device can obtain a detuning quantity, and is used for counteracting the problem of fidelity reduction caused by working frequency deviation of the quantum bit caused by an AC Stark effect.
Based on the same inventive concept, the present application further provides a device for adjusting a qubit control signal, referring to the figure, the device 100 for adjusting a qubit control signal includes:
a physical model acquisition module 110 configured to acquire a physical model for acquiring a theoretical expectation of a change in quantum state information of a qubit with a mismatch amount, the mismatch amount being an amount by which a frequency of the qubit control signal deviates from a bit frequency;
an experimental data acquisition module 120 configured to perform an APE experiment on the qubit to acquire experimental data including a correspondence of quantum state information of the qubit and a detuning amount;
a determination module 130 configured to determine whether the experimental data meets a requirement based on a physical model and the experimental data;
an adjustment module 140 configured to adjust the qubit control signal based on the experimental data as required.
It is understood that the physical model obtaining module 110, the experimental data obtaining module 120, the judging module 130, and the adjusting module 140 may be combined in one device to be implemented, or any one of the modules may be split into a plurality of sub-modules, or at least part of functions of one or more of the obtaining module 110, the experimental data obtaining module 120, the judging module 130, and the adjusting module 140 may be combined with at least part of functions of other modules to be implemented in one functional module. At least one of the physical model acquisition module 110, the experimental data acquisition module 120, the judgment module 130, and the adjustment module 140 may be at least partially implemented as a computer program module, which may perform the functions of the corresponding module when the program is run by a computer.
Based on the same inventive concept, the application also provides a quantum computer, which comprises the adjusting device of the quantum bit control signal provided by the application.
Based on the same inventive concept, the present application also provides a readable storage medium having stored thereon a computer program, which when executed, can implement the method for adjusting the qubit control signal provided in an embodiment of the present application.
In the description of the present specification, a description of the terms "one embodiment," "some embodiments," "examples," or "particular examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments. Further, one skilled in the art can engage and combine the different embodiments or examples described in this specification.
The foregoing is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art will make any equivalent substitution or modification to the technical solution and technical content disclosed in the invention without departing from the scope of the technical solution of the invention, and the technical solution of the invention is not departing from the scope of the invention.
Claims (12)
1. A method of adjusting a qubit control signal, comprising:
acquiring a physical model, wherein the physical model is used for acquiring theoretical expectation of the change of quantum state information of a quantum bit along with the tuning-off quantity, and the tuning-off quantity is the quantity of the frequency deviation bit frequency of the quantum bit control signal;
performing an APE experiment on the quantum bit to obtain experimental data, wherein the experimental data comprises a corresponding relation between quantum state information and detuning amount of the quantum bit;
judging whether the experimental data meets the requirements or not based on a physical model and the experimental data;
the qubit control signal is adjusted based on the experimental data meeting requirements.
2. The method of tuning a qubit control signal of claim 1 wherein the physical model comprises:
the change relation of the quantum state information along with the tuning quantity satisfies the following conditions:
y＝Acos[2πf 0 (x-Φ)]+C
wherein y is quantum state information, x is detuning amount, A, f 0 And C and phi are parameters of the physical model.
3. The method for adjusting a qubit control signal according to claim 1, wherein the performing an APE experiment on the qubit to obtain experimental data, the experimental data including a correspondence between quantum state information and a detuning amount of the qubit, includes:
acquiring N pairs of quantum bit control signals, wherein any pair of the quantum bit control signals is used for enabling quantum state information of the quantum bit to change from a first quantum state to a second quantum state and from the second quantum state to the first quantum state;
determining a first scanning interval and a first scanning step length of the detuning quantity, updating the frequency of the N pairs of quantum bit control signals according to the first scanning interval and the first scanning step length, and applying the updated N pairs of quantum bit control signals to the quantum bits to obtain first data of the quantum state information changing along with the detuning quantity after the current N pairs of quantum bit control signals act;
at least two sets of first data are acquired.
4. The method for adjusting a qubit control signal according to claim 1, wherein the determining whether the experimental result meets the requirement based on the physical model and the experimental result comprises:
and judging whether the experimental result meets the requirements or not by using the fitting goodness of the physical model and the experimental data.
5. The method of adjusting a qubit control signal according to claim 4, wherein the determining whether the experimental result meets a requirement by using a goodness of fit for the physical model and the experimental data comprises:
constructing a first formula, wherein the first formula is as follows:
wherein R is 2 To the extent of fitting, y fit In order to obtain theoretical expectation according to the physical model, y raw In order to make the data of the experiment,is the average of the experimental data;
and comparing the fitting degree with a first preset threshold value by using the first formula, and judging whether the experimental data meets the requirement.
6. The method for adjusting a qubit control signal according to claim 5, wherein the obtaining the fitting degree by using the first formula and comparing the fitting degree with a first preset threshold value, and determining whether the experimental data meets the requirement, comprises:
judging the R 2 Whether the first preset threshold value is larger than the first preset threshold value;
if yes, judging that the experimental result meets the requirement;
if not, judging that the experimental result is not in accordance with the requirement.
7. A method of conditioning a qubit control signal according to claim 3, wherein said conditioning the qubit control signal based on the experimental data meeting the requirements comprises:
acquiring at least two groups of first data meeting the requirements;
respectively obtaining detuning amounts corresponding to the quantum state information in the maximum value points in the first data;
obtaining at least two closest or equal detuning amounts in the detuning amounts corresponding to the maximum value point;
judging whether the closest or equal at least two detuning amounts meet the requirement or not based on the maximum value and the minimum value of the closest or equal at least two detuning amounts;
if so, adjusting the qubit control signal based on the at least two detunes.
8. The method of claim 7, wherein said determining whether the closest or equal at least two detuning amounts meet a requirement comprises:
obtaining the difference value between the maximum value and the minimum value in the closest or equal at least two tuning amounts;
judging whether the absolute value of the difference value is not larger than a second preset threshold value or not;
if yes, judging that the obtained at least two detuning amounts meet the requirements.
9. The method of adjusting a qubit control signal of claim 7 wherein the adjusting the qubit control signal based on the at least two detunes comprises:
and adjusting the frequency of the qubit control signal by taking the average value of the at least two detuning amounts as the detuning amount.
10. An apparatus for adjusting a qubit control signal, comprising:
a physical model acquisition module configured to acquire a physical model for acquiring a theoretical expectation of a change in quantum state information of a qubit with a mismatch amount, the mismatch amount being an amount by which a frequency of the qubit control signal deviates from a bit frequency;
an experimental data acquisition module configured to perform an APE experiment on the qubit to acquire experimental data including a correspondence of quantum state information of the qubit and a detuning amount;
a judging module configured to judge whether the experimental data meets a requirement based on a physical model and the experimental data;
an adjustment module configured to adjust the qubit control signal based on the experimental data as required.
11. A readable storage medium having stored thereon a computer program, which when executed is capable of implementing a method of adjusting a qubit control signal according to any one of claims 1 to 9.
12. A quantum computer comprising the adjustment device of the qubit control signal of claim 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210915172.6A CN117521824A (en) | 2022-07-29 | 2022-07-29 | Quantum bit control signal adjusting method and device and quantum computer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210915172.6A CN117521824A (en) | 2022-07-29 | 2022-07-29 | Quantum bit control signal adjusting method and device and quantum computer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117521824A true CN117521824A (en) | 2024-02-06 |
Family
ID=89750062
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210915172.6A Pending CN117521824A (en) | 2022-07-29 | 2022-07-29 | Quantum bit control signal adjusting method and device and quantum computer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117521824A (en) |
-
2022
- 2022-07-29 CN CN202210915172.6A patent/CN117521824A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11593698B2 (en) | Performing a calibration process in a quantum computing system | |
| Locatelli | Simulated annealing algorithms for continuous global optimization: convergence conditions | |
| CN114578121B (en) | High-voltage measurement method, system and device | |
| CN115493622A (en) | Hemispherical resonant gyroscope temperature compensation method based on fuzzy control and Gaussian process | |
| CN117521824A (en) | Quantum bit control signal adjusting method and device and quantum computer | |
| WO2023143457A1 (en) | Method and apparatus for determining high-energy-state regulation and control signal of quantum bit, and quantum computer | |
| WO2023273870A1 (en) | Method and apparatus for determining multi-qubit measurement result, and quantum computer | |
| Feeny | Fast multifractal analysis by recursive box covering | |
| CN115700613B (en) | Quantum bit control signal optimization method and device and quantum computer | |
| CN115700385A (en) | Method for acquiring direct current crosstalk coefficient and direct current crosstalk matrix between quantum bits | |
| von Schroeder | Stable feature selection with applications to MALDI imaging mass spectrometry data | |
| US20130179121A1 (en) | Calculating apparatus, measuring apparatus, electronic device, program, recording medium and calculating method | |
| CN115600678B (en) | Quantum bit read signal optimization method and device and quantum computer | |
| CN115840126B (en) | Quantum bit frequency acquisition method, quantum measurement and control system and quantum computer | |
| CN115598490B (en) | Quantum chip testing method and device, quantum measurement and control system and quantum computer | |
| US20210116499A1 (en) | Calibration method, calibration apparatus, and program | |
| CN113780353B (en) | Satellite navigation automatic interpretation method based on machine learning | |
| CN118100922A (en) | Acquisition method and device of AC modulation spectrum and quantum computer | |
| US20240070513A1 (en) | Method for determining crosstalk of quantum bits, quantum control system, and quantum computer | |
| CN115577784B (en) | Method and device for calibrating qubit regulation signal and readable storage medium | |
| CN108259036B (en) | VCO, frequency calibration method thereof, electronic device, and computer storage medium | |
| CN111526655B (en) | Tuning method and device for radio frequency quadrupole accelerator and storage medium | |
| CN117371545A (en) | Acquisition method and device of AC modulation spectrum and quantum computer | |
| CN108233923B (en) | VCO, frequency calibration method thereof, electronic device, and computer storage medium | |
| CN115664412A (en) | Crystal oscillator adjusting method and device and readable storage medium |
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 |