The present disclosure relates to the quantum computation field, and in particular, to a quantum state information processing system, a quantum measurement and control system, and a quantum computer.
Quantum state information refers to a quantum state of a qubit, and basic quantum states include state |0) and state |1). After the qubit is operated, the quantum state of the qubit changes. It is reflected that on a quantum chip, after the quantum chip is executed, a quantum state of the qubit changes, that is, execution result of the quantum chip is obtained. The execution result is carried and transmitted by a qubit readout signal (generally an analog signal). Rapidly parsing a quantum state of a qubit by using a qubit reading signal is a key work for understanding execution performance of a quantum chip. There is no hardware system for effectively parsing a quantum state of a qubit in conventional technologies.
Therefore, how to provide a hardware system for parsing a quantum state of a qubit becomes a technical problem to be urgently solved by those skilled in the art.
An objective of embodiments of the present disclosure is to provide a quantum state information processing system, a quantum measurement and control system, and a quantum computer, to solve a problem of lacking a hardware system for effectively parsing a quantum state of a qubit in conventional technologies.
An embodiment of the present disclosure provides a quantum state information processing system, where quantum state information is included in an analog signal collected from a qubit, and the quantum state information processing system includes:
Optionally, the demodulation module includes:
Optionally, the filter includes N adders, the N adders are classified into a plurality of sub-combinations, and adders in each sub-combination synchronously execute an addition operation.
Optionally, the filter further includes a first multiplier, the plurality of sub-combinations are connected in a cascaded manner, the first sub-combination of the filter includes ┌N/2┐ adders, input of the first sub-combination is output of the first multiplier, and input of a sub-combination at a current stage in cascade is output of a sub-combination at a previous stage.
Optionally, the frequency mixing module includes:
Optionally, the determining module includes:
Optionally, the quantum state information processing system further includes:
Optionally, the quantum state information processing system further includes:
Optionally, the sampling module includes an ADC.
Optionally, the sampling module, the frequency mixing module, the demodulation module, and the determining module are implemented by using an FPGA, a DSP, or an MCU.
An embodiment of the present disclosure further provides a quantum measurement and control system, including the quantum state information processing system according to any one of the foregoing feature descriptions, where the quantum state information processing system is configured to acquire corresponding quantum state information from output information of a qubit.
An embodiment of the present disclosure further provides a quantum computer, including the quantum measurement and control system.
Compared with the conventional technologies, an embodiment of the present disclosure may have the following beneficial effects.
In the quantum state information processing system provided in the embodiment, a sampling module is used to perform sampling processing on an analog signal collected from a qubit, a frequency mixing module is used to perform mixing processing on the sampled signal, a demodulation module is used to perform demodulation processing on a mixed signal, and a determining module is used to perform state classification on a demodulated signal by using a state classification equation, so as to acquire quantum state information. According to the quantum state information processing system in the present application, a hardware system architecture is provided, which fills a technical gap of a hardware system for parsing a quantum state of a qubit in conventional technologies.
The quantum measurement and control system and the quantum computer provided in the embodiments belong to a same inventive concept with the quantum state information processing system, and therefore have same beneficial effect, and details are not described herein again.
The following describes specific implementations of the present disclosure with reference to the accompanying drawings. The advantages and features of the embodiments will be more apparent based on the following descriptions and claims. It should be noted that, the accompanying drawings all use a very simplified form and a non-accurate proportion for conveniently and clearly assisting in description of the embodiments.
In the description of the present disclosure, it should be understood that, orientations or position relationships indicated by the terms “center”, “on”, “below”, “left”, “right”, and the like are orientations or position relationships based on the accompanying drawings. These terms are merely intended to facilitate the description of the present disclosure and simplify the description, rather than indicating or implying that the referred apparatus or element must have a particular orientation or be constructed and operated in a particular orientation. Therefore, these terms should not be interpreted as limiting embodiments of the present disclosure.
In addition, the terms “first”, “second”, and the like are merely intended for a purpose of description, and shall not be understood as an indication or implication of relative importance or implicit indication of the number of indicated technical features. Therefore, the features defined by “first”, “second”, and the like may indicate or imply that one or more of the features are included. In the descriptions of the present disclosure, “a plurality of” means at least two, for example, two or three, unless otherwise specifically stated.
Referring to
Different from conventional technologies, the quantum state information processing system provided in this embodiment uses the sampling module to perform sampling processing on an analog signal acquired from a qubit, the frequency mixing module to perform mixing processing on a sampling signal, the demodulation module to perform demodulation processing on a mixed signal, and the determining module to perform state classification on a demodulated signal by using a state classification equation, so as to acquire quantum state information. According to the quantum state information processing system in the present application, a hardware system architecture is provided, which fills a technical gap of a hardware system for parsing a quantum state of a qubit in the conventional technologies. In this embodiment, the sampling module may be implemented by using an analog to digital converter (Analog to Digital Converter, ADC). The quantum state information processing system may be implemented by using a field programmable gate array (Field Programmable Gate Array, FPGA), a digital signal processor (Digital Signal Processor, DSP) or a microcontroller unit (Microcontroller Unit, MCU), and the sampling module, the frequency mixing module, the demodulation module, and the determining module may be integrated into the FPGA, the DSP or the MCU. A parsing process of a qubit readout signal may generally be roughly divided into IQ demodulation, filtering and integration. In this parsing process, communication between a qubit measurement and control system and a PC may be established in principle, and then the parsing process is performed on collected data on the PC to complete parsing of quantum state information. However, the solution of using a PC to implement parsing of quantum state information is unacceptable in terms of data processing delay relative to a typical coherence time at a microsecond level of a superconducting qubit, and de-coherence of a qubit will completely lose real-time performance of the quantum state information. The inventors found that using an FPGA to implement parsing of quantum state information may complete all data processing procedures required in a time at hundreds of nanoseconds level or even tens of nanoseconds level. Therefore, in this embodiment, the quantum state information processing system is preferably implemented by using an FPGA.
Specifically, referring to
A specific structure of a filter is described briefly in the following. Referring to
A structure of the plurality of adders may be set in the following manners. When a quantity of first multipliers is an even number, if a quantity of outputs of each sub-combination is an even number, the plurality of adders are arranged according to the following structure: A quantity of adders in a sub-combination at a previous stage is twice a quantity of adders, connected to the adders at the previous stage, in a sub-combination at a current stage, and reference may be made to the structure shown in
If a quantity of outputs of a specific sub-combination is an odd number, the sub-combination is defined as a redundant sub-combination, the plurality of adders are arranged according to the following structure: An adder is added following a sub-combination at the last stage, and the adder is defined as a first redundancy adder. Two input terminals of the redundancy adder are respectively connected to an output of the last sub-combination and an output of the redundancy sub-combination, and reference may be made to the structure shown in
When the quantity of the first multipliers is an odd number, one of the outputs is defined as a redundant output, and the plurality of adders are arranged according to the following structure: An adder is added following a sub-combination at the last stage, and the adder is defined as a second redundant adder. Two input terminals of the second redundancy adder are respectively connected to an output of the last sub-combination and the redundancy output, and reference may be made to the structure shown in
It should be noted that, the examples shown in
Specifically, when the quantity of the first multipliers is an integer power of 2, a quantity of adders in a sub-combination at a previous stage is twice a quantity of adders in a sub-combination at a current stage, and reference may be made to the structure shown in
When the quantity of the first multipliers is not an integer power of 2, for example, when the quantity of the first multipliers is 9, reference may be made to the structure shown in
In this embodiment, the frequency mixing module includes a numerically controlled oscillator (NCO) and a second multiplier, where the numerically controlled oscillator is configured to output a local oscillator signal; and the second multiplier is configured to perform multiply the local oscillator signal and the sampled signal to output the mixed signal.
Specifically, the numerically controlled oscillator (NCO) is also referred to as a direct digital synthesizer (DDS). A main function of the NCO is to generate a sine/cosine waveform sequence with frequency and phase adjustable, and relatively good data precision can be ensured. Implementation methods of the NCO mainly include a real-time calculation method and a table lookup method. It is difficult for the real-time calculation method to balance calculation accuracy and calculation time overheads when a waveform with relatively high frequency is generated. A system used herein requires the NCO to provide high-frequency local oscillator signals for the mixer, which require high speed and precision. Therefore, the table lookup method is used to implement replacement of time with space, that is, to calculate waveform values of each point in advance by using a phase point as an independent variable, and the waveform values are converted to binary and addressed and stored in a phase sequence. A main implementation principle is shown in
An output frequency fout is determined by a value of an output Δφ of the phase accumulator and a frequency fclk of the system, and a relationship therebetween is as follows:
The output of the phase accumulator progresses evenly with time, which may be used as an address input of a read-only memory look-up table (ROM LUT) in which sine and cosine waveform sampling is stored in advance, then a target waveform sampling point is found by using the look-up table, and quantized data of a required waveform data point is output by the ROM. For the quantum state readout system herein, it needs to make the NCO module generate two-channel sinusoidal and cosine signals having a same frequency but a phase difference of π/2 as a target bit readout cavity by setting an appropriate frequency control word, so as to provide a standard carrier for mixing I-Q channels with an original sampled signal.
Corresponding to the I-Q channels, the second multiplier is also divided into two channels, and one of the multipliers is used as an example. Inputs of the two multipliers are respectively an original signal and a waveform generated from the NCO, and an output of the second multiplier is the output of the frequency mixing module.
Still referring to
Further, since the inventors also noted that, a bit width of a signal is expanded to prevent overflow in an operation process of mixing, filtering, integration, and the like, a waveform length is not divided in the integration and accumulation operation, and the bit width exceeds 50 bits after several layers of multiplication and accumulation, resulting in a large number of redundant bits unnecessarily occupying many additional computing resources. The quantum state information processing system provided in the present application further uses a bit width control module to truncate the demodulated signal based on a binary shift operation to adjust a bit width of the demodulated signal. Unnecessary data bits are truncated, and a matching problem between data is uniformly processed, so as to ensure that a correct operation result is output, thereby saving a large amount of computing resources. Specifically, the quantum state information processing system may further include a bit width control module, and the bit width control module is configured to truncate the demodulated signal based on the binary shift operation to adjust the bit width of the demodulated signal.
Based on a same inventive concept, an embodiment further provides a quantum measurement and control system, including the quantum state information processing system according to any one of the foregoing feature descriptions, where the quantum state information processing system is configured to acquire corresponding quantum state information from output information of a qubit.
Based on a same inventive concept, an embodiment further provides a quantum computer, including the quantum measurement and control system in the foregoing feature descriptions.
In the description of this specification, the description with reference to the terms “an embodiment”, “some embodiments”, “an example”, “a specific example” or the like means that specific features, structures, materials, or characteristics described in combination with the embodiments or examples are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the foregoing terms does not necessarily refer to a same embodiment or example. Moreover, the described specific features, structures, materials, or characteristics may be combined in any one or more embodiments in an appropriate manner. In addition, different embodiments or examples described in this specification may be combined and grouped by those skilled in the art.
The foregoing are merely preferred embodiments of the present disclosure, and have no limitation to the present disclosure. Any variation, such as equivalent replacement or modification, made by a person skilled in the art to the technical solutions and technical content disclosed in the present disclosure without departing from the scope of the technical solutions of the present disclosure shall belong to content of the technology solutions of the present disclosure and still belong to the protection scope of the present disclosure. cm What is claimed is:
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110625588.X | Jun 2021 | CN | national |
This application is a continuation of International Application No.PCT/CN2022/096176, filed on May 31, 2022, which claims priority to Chinese Patent Application No. CN202110625588.X, filed on Jun. 4, 2021 and entitled “QUANTUM STATE INFORMATION PROCESSING SYSTEM, QUANTUM MEASUREMENT AND CONTROL SYSTEM, AND QUANTUM COMPUTER”. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2022/096176 | May 2022 | WO |
| Child | 18497148 | US |