CN113177641A - Feedback optimization method of quantum bit control pulse - Google Patents
Feedback optimization method of quantum bit control pulse Download PDFInfo
- Publication number
- CN113177641A CN113177641A CN202110533099.1A CN202110533099A CN113177641A CN 113177641 A CN113177641 A CN 113177641A CN 202110533099 A CN202110533099 A CN 202110533099A CN 113177641 A CN113177641 A CN 113177641A
- Authority
- CN
- China
- Prior art keywords
- waveform
- gate
- probability
- state
- quantum
- 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 23
- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000005457 optimization Methods 0.000 title claims abstract description 17
- 239000003550 marker Substances 0.000 claims abstract description 21
- 238000007493 shaping process Methods 0.000 claims abstract description 4
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
Images
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
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
- H03D7/00—Transference of modulation from one carrier to another, e.g. frequency-changing
- H03D7/16—Multiple-frequency-changing
Landscapes
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mathematical Analysis (AREA)
- Computing Systems (AREA)
- Evolutionary Computation (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Computational Mathematics (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Data Mining & Analysis (AREA)
- General Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Software Systems (AREA)
- Artificial Intelligence (AREA)
- Power Engineering (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention provides a feedback optimization method of a quantum bit control pulse, belonging to the technical field of quantum computation, and the technical scheme provided by the invention comprises the following steps: adding data mark points (Marker) at certain intervals aiming at the waveform output of the AWG, shaping microwave pulses corresponding to the X gate by adjusting the amplitude of each Marker point, and repeatedly reading the quantum state after microwave control, wherein the feedback signal in the optimization process is the probability of reading the quantum state and turning the quantum state to the |1> state. The invention can improve the fidelity of single quantum bit control.
Description
Technical Field
The invention relates to the technical field of quantum computation, in particular to a feedback optimization method of quantum bit control pulse.
Background
The resulting output of the quantum computation depends on the operation of the sequence of quantum gates on the initial state of the qubit, however, since for a single qubit the sequence of quantum gates acting on it operates in series, the errors caused by a single quantum gate will accumulate at the input of the next quantum gate. That is, the accuracy of the quantum computation output will decrease exponentially with the number of gate operations that are applied to a single qubit in the operation. For example, assuming a single bit gate operation with a fidelity of 99.9%, the accuracy of the final result after applying 1000 identical single bit gates is only about 36.77%. For a general quantum algorithm, obtaining a valuable calculation result generally requires a quantum gate operation of higher order of magnitude on a single qubit. Therefore, the fidelity of the quantum gate operation will have a direct impact on the accuracy of the quantum computation output.
For superconducting quantum computation, a single quantum bit gate is realized by respectively connecting two ends of an IQ mixer to two output channels of an Arbitrary Waveform Generator (AWG), modulating a microwave signal accessed by a local oscillator end (local) of the IQ mixer by using an intermediate frequency signal output by the AWG, and outputting a modulated Radio Frequency (RF) to realize the operation of the single quantum bit gate. However, since the IQ mixer is not an ideal device, the output RF signal is far from the ideal signal in the spectrum, i.e. there are some spurious signals around the target frequency. The most common current Transmon qubits are less non-harmonic, so that an undesired waveform output often results in leakage to higher energy levels. In addition, the imperfect RF waveform output also results in the inability to calibrate a perfect control waveform. The qubit gate fidelity improvement schemes commonly used at present are some analytic schemes, such as the widely used adiabatic derivative modification scheme (Drag), which can reduce the leakage of qubits to the hilbert space outside the computational basis.
Disclosure of Invention
In order to solve the technical problem, the invention provides a feedback optimization method of a quantum bit control pulse, and the fidelity of a single-bit gate can be further improved through waveform correction.
The technical scheme of the invention is as follows:
adding data mark points (Marker) at certain intervals for the waveform output part of the AWG operated by the single-bit gate, shaping microwave pulses corresponding to the X gate by adjusting the amplitude of each Marker point, and repeatedly reading the quantum state after microwave control, wherein the feedback signal in the optimization process is the probability that the read quantum state is overturned to the |1> state.
To amplify the error of a single X gate, the control microwave can be extended from a single X gate to an odd number of X gate operations. The feedback optimization scheme can be used for optimizing an X gate, and can also be expanded to a Y gate, an X/2 gate and a Y/2 gate, the realization idea of the Y gate is consistent with that of the X gate, the X/2 gate and the Y/2 gate only need to increase the number of corresponding gate operations to 2n, wherein n is a positive odd number.
Considering that the sampling rate of the general AWG output signal is about 109I.e. one sample every 1ns, so that a maximum of 10 can be set every second, irrespective of the constraints of computing power9And the feedback optimization scheme can realize ns-level signal fine adjustment.
In addition, since the analysis schemes such as the commonly used Drag correction also belong to the waveform shaping scheme in nature, and the difference is that the Drag correction is to add the derivative waveform of the original output signal to the output of the AWG and multiply the amplitude factor, the proposed feedback optimization scheme actually completely covers the commonly used Drag correction scheme, and theoretically can obtain the single-bit gate operation under higher fidelity.
The method comprises the following specific steps:
1) randomly adjusting the amplitude of the selected Marker point;
2) applying the single-bit gate sequence to the qubit using the new waveform;
3) reading the quantum bit state to obtain the probability of obtaining |1 >;
4) whether the probability of obtaining the |1> is larger than a preset threshold value or not is judged, if yes, circulation is jumped out; otherwise, carrying out the next step;
5) whether the probability of this time getting |1> is greater than the probability of the last time getting |1>,
if so, the pulse waveform is set as the new waveform after the adjustment, and the step 1 is repeated
Otherwise, the pulse waveform is restored to the waveform before the adjustment, and the step 1) is repeated.
Further, in the above-mentioned case,
and 5) comparing the new acting waveform with the waveform calibrated by the traditional method and measuring to obtain the probability of the state |1> for the first waveform correction.
If the probability of obtaining the state |1> of the new waveform is larger than that before correction, the AWG output is set as the new waveform, and the step 1) is carried out; if the probability of obtaining the |1> state of the new waveform is not greater than the probability before the correction, keeping the AWG output before the correction, and entering step 1).
The invention can increase technical reserve and hatch quantum computing related derivative products.
Drawings
FIG. 1 is a schematic flow chart of a qubit control pulse feedback optimization scheme.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention, and based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the scope of the present invention.
In this embodiment, the feedback optimization scheme of the qubit control pulse is implemented as follows:
and S1, selecting a certain threshold value a as a target threshold value to be reached by the optimization, wherein the selection of the threshold value a is generally higher than the maximum fidelity which can be obtained by adopting a conventional calibration scheme. Selecting a certain step length b as the step length of Marker point amplitude iteration in the optimization, wherein the selection of b is usually limited by the resolution of AWG output amplitude;
s2, calibrating the needed optimized AWG waveform output by using a conventional single-bit gate calibration scheme;
s3, adding Marker points in the output waveform of the AWG at certain intervals, wherein the selection interval of the Marker points is generally limited by the sampling rate of the AWG waveform and the computing capacity of the optimization equipment;
and S4, as shown in step A of FIG. 1, randomly correcting the amplitude of all the selected Marker points by a certain step b. The correction scheme is to generate a random vector consisting of b,0 and-b, the length of the vector is consistent with the number of Marker points, and then the AWG waveform amplitude corresponding to the Marker points is added with elements in the corresponding vector. For example, for the correction vector (b, b, -b,0, -b … …), the amplitude of the first Marker point of the AWG is added to b, the amplitude of the second Marker point is added to b, the amplitude of the third Marker point is subtracted from b, the amplitude of the fourth Marker point remains unchanged, and the amplitude of the fifth Marker point is subtracted from b … … until the amplitudes of all Marker points are corrected;
s5, applying the microwave sequence composed of new waveforms to the quantum bit, amplifying the error caused by a single gate by using the sequence composed of odd number of waveforms for an X gate and a Y gate, and amplifying the error caused by a single gate by using the sequence composed of 2n waveforms for an X/2 gate and a Y/2 gate, wherein n is an odd number;
s6, measuring the qubits for multiple times, comparing whether the probability of obtaining |1> by reading the qubit state after the qubit state is acted on a new waveform by S5 is greater than or equal to a preset a, and calling out a cycle if the probability is greater than or equal to a; if less than a, go to S7;
s7, comparing the probability of |1> state obtained by measuring the new waveform after S5 acts on the new waveform and before the waveform is corrected, and comparing the new waveform with the probability of |1> state obtained by measuring the waveform calibrated by the traditional method after the waveform is acted on the first waveform correction;
s8, if the probability of obtaining |1> state of the new waveform is larger than that before correction, setting the AWG output as the new waveform, and entering S4; if the probability of the new waveform obtaining the |1> state is not greater than before the correction, the AWG output is maintained before the correction, and the process proceeds to S4.
The above description is only a preferred embodiment of the present invention, and is only used to illustrate the technical solutions of the present invention, and not to limit the protection scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (8)
1. A feedback optimization method of a quantum bit control pulse is characterized in that,
adding data mark points, namely Marker points, at intervals aiming at the waveform output of the AWG, shaping microwave pulses corresponding to a single-bit gate by adjusting the amplitude of each Marker point, and repeatedly reading the quantum state after microwave control, wherein a feedback signal in the optimization process is the probability of reading the quantum state and turning the quantum state to the |1> state.
2. The method of claim 1,
to amplify the error of a single bit gate, the control microwave can be extended from a single bit gate to an odd number of single bit gate operations.
3. The method of claim 2,
the single bit gate comprises an X gate, a Y gate, an X/2 gate or a Y/2 gate.
4. The method of claim 3,
the Y door realizes that the train of thought is unanimous with the X door, X/2 door and Y/2 door only need to promote the number that corresponds the door operation to 2n can, wherein n is positive odd number.
5. The method of claim 1,
AWG waveform output is set to a maximum of 10 per second9And (4) Marker point.
6. The method of claim 1,
the method comprises the following specific steps:
1) randomly adjusting the amplitude of the selected Marker point;
2) applying the single-bit gate sequence to the qubit using the new waveform;
3) reading the quantum bit state to obtain the probability of obtaining |1 >;
4) whether the probability of obtaining the |1> is larger than a preset threshold value or not is judged, if yes, circulation is jumped out; otherwise, carrying out the next step;
5) whether the probability of this time getting |1> is greater than the probability of the last time getting |1>,
if so, the pulse waveform is set as the new waveform after the adjustment, and the step 1 is repeated
Otherwise, the pulse waveform is restored to the waveform before the adjustment, and the step 1) is repeated.
7. The method of claim 6,
and 5) comparing the new acting waveform with the waveform calibrated by the traditional method and measuring to obtain the probability of the state |1> for the first waveform correction.
8. The method of claim 7,
if the probability of obtaining the state |1> of the new waveform is larger than that before correction, the AWG output is set as the new waveform, and the step 1) is carried out; if the probability of obtaining the |1> state of the new waveform is not greater than the probability before the correction, keeping the AWG output before the correction, and entering step 1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110533099.1A CN113177641A (en) | 2021-05-17 | 2021-05-17 | Feedback optimization method of quantum bit control pulse |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110533099.1A CN113177641A (en) | 2021-05-17 | 2021-05-17 | Feedback optimization method of quantum bit control pulse |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113177641A true CN113177641A (en) | 2021-07-27 |
Family
ID=76929080
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110533099.1A Pending CN113177641A (en) | 2021-05-17 | 2021-05-17 | Feedback optimization method of quantum bit control pulse |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113177641A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113688997A (en) * | 2021-08-24 | 2021-11-23 | 山东浪潮科学研究院有限公司 | Method, device and equipment for single-bit multi-quantum gate fusion optimization |
| CN117669752A (en) * | 2024-01-29 | 2024-03-08 | 山东云海国创云计算装备产业创新中心有限公司 | Method, system, equipment and medium for optimizing quantum bit logic gate parameters |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108334952A (en) * | 2017-11-24 | 2018-07-27 | 南京航空航天大学 | A kind of novel universal quantum door and quantum wire optimization method |
| US10469087B1 (en) * | 2018-10-08 | 2019-11-05 | Microsoft Technology Licensing, Llc | Bayesian tuning for quantum logic gates |
| CN112331693A (en) * | 2020-11-02 | 2021-02-05 | 深圳市福田区南科大量子技术与工程研究院 | Easily-expandable high-fidelity superconducting quantum chip structure and operation method |
| CN112418429A (en) * | 2019-08-23 | 2021-02-26 | 中国科学技术大学 | Method and system for realizing CZ door |
-
2021
- 2021-05-17 CN CN202110533099.1A patent/CN113177641A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108334952A (en) * | 2017-11-24 | 2018-07-27 | 南京航空航天大学 | A kind of novel universal quantum door and quantum wire optimization method |
| US10469087B1 (en) * | 2018-10-08 | 2019-11-05 | Microsoft Technology Licensing, Llc | Bayesian tuning for quantum logic gates |
| CN112418429A (en) * | 2019-08-23 | 2021-02-26 | 中国科学技术大学 | Method and system for realizing CZ door |
| CN112331693A (en) * | 2020-11-02 | 2021-02-05 | 深圳市福田区南科大量子技术与工程研究院 | Easily-expandable high-fidelity superconducting quantum chip structure and operation method |
Non-Patent Citations (2)
| Title |
|---|
| JOSÉ CAPMANY ET AL.: "Realization of Single-Photon Frequency-Domain Qubit Channels Using Phase Modulators", 《IEEE PHOTONICS JOURNAL》 * |
| 李志远: "超导量子器件的制备和操控", 《中国博士学位论文全文数据库（基础科学辑）》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113688997A (en) * | 2021-08-24 | 2021-11-23 | 山东浪潮科学研究院有限公司 | Method, device and equipment for single-bit multi-quantum gate fusion optimization |
| CN113688997B (en) * | 2021-08-24 | 2023-06-02 | 山东浪潮科学研究院有限公司 | Method, device and equipment for fusion optimization of single-bit multi-quantum gate |
| CN117669752A (en) * | 2024-01-29 | 2024-03-08 | 山东云海国创云计算装备产业创新中心有限公司 | Method, system, equipment and medium for optimizing quantum bit logic gate parameters |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113177641A (en) | Feedback optimization method of quantum bit control pulse | |
| CN100481730C (en) | Method for calibrating digital-to-analog converter and digital-to-analog converter | |
| US7501965B2 (en) | Correcting for errors that cause generated digital codes to deviate from expected values in an ADC | |
| US4647873A (en) | Adaptive linear FM sweep corrective system | |
| CN109409526B (en) | Calibration method for single quantum logic gate operation | |
| CN113809992A (en) | Machine learning based digital predistortion for power amplifiers | |
| US20220200540A1 (en) | Model trainer for digital pre-distorter of power amplifiers | |
| CN101082666A (en) | Method for realizing high precision modulating radar pulse signal based on automatic test system | |
| US10211844B1 (en) | Minimum search length analog to digital converter | |
| CN109406875B (en) | Quantum bit frequency calibration method based on Ramsey interference experiment | |
| CN113659984B (en) | Capacitance mismatch calibration method and system of successive approximation type analog-to-digital converter | |
| CN108833145B (en) | Segmented two-dimensional predistortion system and method using self-organizing mapping network | |
| Kasher et al. | Memory-efficient SFDR-optimized post-correction of analog-to-digital converters via frequency-selective look-up tables | |
| WO2020178954A1 (en) | Receiver device and reception method | |
| US7304591B2 (en) | Method and system for providing a digital signal representing an analog signal | |
| Lundin et al. | Optimal index-bit allocation for dynamic post-correction of analog-to-digital converters | |
| CN110610030A (en) | Power amplifier behavior modeling method based on WaveNet neural network structure | |
| Lundin et al. | A criterion for optimizing bit-reduced post-correction of AD converters | |
| CN103731106B (en) | A kind of segmentation digital pre-distortion method of radio-frequency (RF) power amplification | |
| Björsell et al. | Truncated Gaussian noise in ADC histogram tests | |
| Daponte et al. | Using an interpolation method for noise shaping in A/D converters | |
| CN100530945C (en) | Method and system for stabilizing an amplifier | |
| Tatsumi et al. | A software level calibration based on Bayesian regression for a successive stochastic approximation analog-to-digital converter system | |
| US6781531B2 (en) | Statistically based cascaded analog-to-digital converter calibration technique | |
| Marques et al. | Nonlinear functions in learned iterative shrinkage-thresholding algorithm for sparse signal recovery |
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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210727 |
|
| RJ01 | Rejection of invention patent application after publication |