CN-121981294-A - Dynamic syndrome extraction circuit construction system oriented to neutral atomic quantum computation

CN121981294ACN 121981294 ACN121981294 ACN 121981294ACN-121981294-A

Abstract

The invention discloses a dynamic syndrome extraction circuit construction for neutral atomic quantum computation, which belongs to the technical field of quantum computation and comprises a syndrome extraction construction module library generation unit, a circuit characteristic offline characterization unit and a circuit characteristic online dynamic construction unit, wherein the syndrome extraction construction module library generation unit is used for traversing parameterized syndrome extraction circuit space, generating candidate circuits according to evolution logic of a quantum bit detection area and screening out effective circuits, the circuit characteristic offline characterization unit is used for carrying out structure screening and performance preliminary screening on the effective circuits to obtain feasible circuits and carrying out atomic loss tolerance characterization on the feasible circuits to generate loss tolerance distribution of each feasible circuit on a surface code plane, and the circuit online dynamic construction unit is used for calculating fitness scores of each feasible circuit according to the loss tolerance distribution according to atom loss positions fed back through actual measurement so as to dynamically select an optimal circuit as a next round of syndrome extraction circuit. The invention can dynamically match the atomic loss mode without increasing the circuit cost, effectively inhibit the atomic loss error and improve the fault tolerance performance.

Inventors

LU LIQIANG
LI SHIYU
YIN JIANWEI
TAO CHENNING
ZHOU XIAOYI

Assignees

浙江大学

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A dynamic syndrome extraction circuit construction system for neutral atom quantum computation is characterized by comprising: The syndrome extraction and construction module library generating unit is used for traversing the parameterized syndrome extraction circuit space, generating candidate circuits according to the evolution logic of the quantum bit detection area, screening by a rationality check rule to obtain effective circuits, and forming a syndrome extraction and construction module library by all the effective circuits; The circuit characteristic offline characterization unit is used for carrying out structure screening and performance preliminary screening on the effective circuits in the syndrome extraction and construction module library to obtain feasible circuits, carrying out atomic loss tolerance characterization on the feasible circuits and generating loss tolerance distribution of each feasible circuit on a surface code plane; The circuit online dynamic construction unit is used for calculating the fitness score of each feasible circuit according to the atom loss position fed back by real-time measurement in the quantum calculation process and the loss tolerance distribution, and selecting an optimal circuit as a syndrome extraction circuit of the next round based on the fitness score.
2. The system for constructing the dynamic syndrome extraction circuit for neutral atom quantum computation according to claim 1, wherein the parameterized syndrome extraction circuit space is defined to include configuration parameters including a CNOT gate direction, a CNOT gate alignment mode, a check shift direction and a quantum bit detection area, and is used for jointly determining an arrangement mode of logic gates and an interaction topology among quantum bits in the syndrome extraction construction module.
3. The system for constructing a dynamic syndrome extraction circuit for neutral atomic quantum computation according to claim 1, wherein the generating a candidate circuit according to the evolution logic of the qubit detection region includes dividing the evolution logic of the qubit detection region into a region expansion phase and a region contraction phase, and correspondingly defining a first mode for marking the region in a created or expanded state and a second mode for marking the region in an updated or contracted state, and constructing the candidate circuit by simulating the evolution process of the qubit detection region in the reset layer, the CNOT layer and the measurement layer based on the first mode and the second mode layer by layer.
4. The system for constructing a dynamic syndrome extraction circuit for neutral atom quantum computation of claim 3 wherein said rationality check rule comprises that the qubit detection region in the first mode contains only one check qubit and any two of the qubit detection regions in the second mode are not shrunk to the same check qubit.
5. The system for constructing a dynamic syndrome extraction circuit for neutral atom quantum computation according to claim 1, wherein for the effective circuits in the syndrome extraction and construction module library, three classes are classified for subsequent structure screening according to the evolution trend of the qubit detection area, the classification includes a fixed type in which the qubit detection area remains unchanged in the CNOT layer, an extended type in which the qubit detection area is extended and the check bit is moved during construction, and a contracted type in which the qubit detection area is contracted during construction.
6. The system for constructing the dynamic syndrome extraction circuit for neutral atomic quantum computation according to claim 5, wherein the method for performing structure screening and performance preliminary screening on the effective circuits in the syndrome extraction and construction module library to obtain the feasible circuits comprises performing structure screening on the effective circuits based on structural constraints, wherein the structural constraints comprise that an expansion type circuit and a contraction type circuit cannot be combined in the same sequence, the total number of the expansion type circuit and the contraction type circuit is not more than three, and further performing performance preliminary screening on the circuits after structure screening under a pure Brinell noise environment, and performing logic error rate screening based on Brinell errors to obtain the feasible circuits.
7. The system for constructing the dynamic syndrome extraction circuit for neutral atomic quantum computation according to claim 1 or 6, wherein the step of performing atomic loss tolerance characterization on the feasible circuits to generate loss tolerance distribution of each feasible circuit on the surface code plane comprises sampling all the feasible circuits under a noise model containing atomic loss, counting decoding success rate when atomic loss occurs at each physical position as the atomic loss tolerance of the feasible circuits, and forming the loss tolerance distribution of each feasible circuit for all physical quantum bits on the surface code plane by the atomic loss tolerance of all physical positions.
8. The system for constructing the dynamic syndrome extraction circuit for neutral atomic quantum computation according to claim 1, wherein the calculating the fitness score of each feasible circuit according to the loss tolerance distribution comprises obtaining an atom loss physical position set determined by current round measurement feedback, searching atom loss tolerance values corresponding to each position in the atom loss physical position set from the loss tolerance distribution of each feasible circuit, and calculating the average value of the atom loss tolerance values corresponding to each position as the fitness score of each feasible circuit in the current loss mode.
9. The dynamic syndrome extraction circuit construction system for neutral atom quantum computation according to claim 1 or 8, wherein the selecting an optimal circuit as a syndrome extraction circuit of a next round based on the fitness score comprises: and selecting a feasible circuit with the highest fitness score from feasible circuits matched with the prefix sequences of the executed syndrome extraction building modules as an optimal circuit, and extracting the optimal circuit as a syndrome extraction circuit for the next round of execution.
10. The method for constructing the dynamic syndrome extraction circuit for neutral atom quantum computation is realized by using the dynamic syndrome extraction circuit construction system for neutral atom quantum computation according to any one of claims 1 to 9, and is characterized by comprising the following steps: traversing parameterized syndrome extraction circuit space by utilizing a syndrome extraction construction module library generating unit, generating candidate circuits according to evolution logic of a quantum bit detection area, screening by a rationality check rule to obtain effective circuits, and forming a syndrome extraction construction module library by all the effective circuits; Performing structure screening and performance preliminary screening on the effective circuits in the syndrome extraction and construction module library by using a circuit characteristic offline characterization unit to obtain feasible circuits, and performing atomic loss tolerance characterization on the feasible circuits to generate loss tolerance distribution of each feasible circuit on a surface code plane; And calculating the fitness score of each feasible circuit according to the loss tolerance distribution by utilizing the on-line dynamic circuit construction unit according to the atom loss position fed back by real-time measurement in the quantum calculation process, and selecting an optimal circuit as a syndrome extraction circuit of the next round based on the fitness score.

Description

Dynamic syndrome extraction circuit construction system oriented to neutral atomic quantum computation Technical Field The invention belongs to the technical field of quantum computation, and particularly relates to a dynamic syndrome extraction circuit construction system for neutral atom quantum computation. Background Neutral atomic arrays have become an important platform for scalable fault-tolerant quantum computing due to their flexible qubit layout, large-scale qubit numbers, and high-fidelity reconfigurable interactions. To support such scaling, quantum error correction techniques are typically employed, with surface codes becoming the dominant choice due to their high error thresholds and computational convenience. Implementing the surface code requires detection of physical noise by a syndrome extraction (Syndrome Extraction, SE) circuit, and error correction in conjunction with the decoder. However, neutral atom systems have a special mechanism for non-bubble error-atom loss. Atomic loss removes a qubit from the array, resulting in the failure of all subsequent logic gates that involve that bit. Such errors break the assumption of standard surface code decoders and pose a serious challenge to reliable error correction. Aiming at the atom loss problem, the prior art is mainly improved from two aspects of a decoder and a syndrome extraction circuit: (1) Decoder aspects the prior art enumerates all possible missing positions within the qubit lifecycle by enhancing the detector error model (Detector Error Model, DEM) and generates a weighted model that enables a Minimum-weight perfect match (Minimum-WEIGHT PERFECT MATCHING, MWPM) decoder to indirectly utilize the missing information. (2) In the circuit aspect, in order to detect the loss of data quantum bits as early as possible, a method for modifying a syndrome extraction circuit is proposed in the prior art. For example, study document 1 (named LEVERAGING ATOM LOSS ERRORS IN FAULT TOLERANT QUANTUM ALGORITHMS, using atomic loss error in fault tolerant quantum algorithm) proposes SWAP SE technique, introducing SWAP gate and physical exchange after the last layer of CNOT gate, transferring the lost information of data qubits to check bits, study document 2 (named Relaxing hardware requirements for surface code circuits using time-dynamics, using time dynamics to reduce the hardware requirement of surface code circuit) proposes WIGGLING SE technique, by periodically moving the surface code plane, alternating the roles of data and check qubits. Although the above-described techniques mitigate the effects of atomic loss to some extent, there are significant disadvantages to: (1) The circuit cost is large, and the existing circuit modification scheme often introduces huge resource cost. For example, SWAP SE technology extends the standard four-layer architecture to eight layers, increasing circuit depth and operating time. (2) The existing circuit structure is static and cannot be adjusted according to the specific lost position actually observed in the calculation process. (3) The error correction effect is limited by the inability to optimize for a particular loss pattern, even with the improved approach described above, the logical error rate in the presence of atomic loss is an order of magnitude higher (e.g., still about 20 times higher at a code distance of 5) than in the absence. Therefore, how to design a syndrome extraction circuit which can adapt to the atom loss position, has low cost and can effectively improve the fault tolerance performance of the surface code is a key problem to be solved in the current neutral atomic quantum computing field. Disclosure of Invention In view of the above, the present invention aims to provide a dynamic syndrome extraction circuit construction system for neutral atomic quantum computation, which constructs a construction module library containing different error propagation characteristics through a syndrome extraction construction module library generation unit, generates tolerance distribution of each circuit to atomic loss through a circuit characteristic offline characterization unit, and adaptively selects an optimal syndrome extraction circuit structure by a circuit online dynamic construction unit according to an atomic loss mode detected in real time, thereby realizing dynamic matching of a loss position and circuit fault tolerance characteristics on the premise of not increasing additional circuit layers or significant gate length overhead, maximally inhibiting the influence of atomic loss on logic error rate, and remarkably improving the fault tolerance performance of a neutral atomic quantum computer. In order to achieve the above purpose, the technical scheme provided by the invention is as follows: the embodiment of the invention provides a dynamic syndrome extraction circuit construction system for neutral atomic quantum computation, which comprises the following components: The syndrome extrac