An anti-decoherence quantum state encoding method based on isosceles trapezoidal address array symmetry and a quantum computing system thereof
Patent Information
- Application Number
- CN202611339902.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-01
- Publication Date
- 2026-11-03
AI Technical Summary
Existing anti-decoherence schemes fail to effectively preserve the amplitude and phase information of quantum states, resulting in information loss during the decoherence process. Furthermore, existing schemes suffer from high redundancy, complexity, or experimental difficulty.
A decoherent quantum state encoding method based on the symmetry of an isosceles trapezoidal address array is adopted. The amplitude and phase information of the quantum state are encoded into different spaces of the address array, and the phase information is reconstructed by address symmetry constraints. Closed-loop feedback control is used to suppress the decoherence effect.
It achieves efficient preservation of complete quantum state information on multiple quantum computing platforms, extends coherence time, improves the fidelity of quantum gate operations and quantum state transmission, and does not require increasing physical qubit redundancy.
Smart Images
Figure CN123031906A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of quantum computing and quantum information processing, specifically to a decoherent quantum state encoding method and its quantum computing system based on the symmetry of an isosceles trapezoidal address array. This invention can be applied to quantum computing platforms such as superconducting qubits, ion trap qubits, and photonic qubits, and is particularly suitable for applications requiring the maintenance of phase information integrity in quantum superposition states. Background Technology
[0002] Quantum superposition is a core resource for quantum computing. A qubit's superposition state contains both amplitude and relative phase information, which together determine all the physical information of the quantum state. However, the interaction between quantum systems and their environment leads to decoherence, causing the phase information of quantum superposition states to be lost exponentially over time. This is a major obstacle to the practical application of quantum computing. Existing anti-degradation coherence schemes have the following shortcomings: (a) Dynamic decoupling scheme. The influence of environmental noise is averaged out by applying a specific pulse sequence. However, this scheme depends on the specific form of the noise spectrum and is not applicable to all types of noise environments. Moreover, the optimization of the pulse sequence becomes extremely complex as the number of qubits increases. (ii) Quantum error correction code scheme. Errors are detected and corrected through redundant coding, but each logical qubit requires a large number of physical qubits as redundancy, resulting in huge overhead and making it difficult to implement on a large scale under current quantum hardware conditions. (III) Topological quantum computing scheme. Fault-tolerant computing is achieved by utilizing the topological properties of non-Abelian anyons, which are naturally immune to local perturbations. However, experimental implementation is extremely difficult and has not yet been verified on a scalable platform. (iv) Geometric quantum computing schemes. The global properties of geometric phase are used to resist local noise. However, existing schemes only utilize phase geometry and do not simultaneously map the complete information of the quantum state to a higher-dimensional geometric structure. Therefore, amplitude decay and phase loss caused by decoherence still exist. Therefore, existing anti-decoherence schemes suffer from the problem of losing quantum state amplitude and phase information during the decoherence process, and there is no encoding scheme that can simultaneously map the complete information of the quantum state into the geometric structure to achieve preservation. To address the above problems, this invention provides a decoherent quantum state encoding method and its quantum computing system based on the symmetry of an isosceles trapezoidal address array. Summary of the Invention
[0003] This invention aims to solve the technical problem of losing quantum state amplitude and phase information during decoherence in existing anti-decoherence schemes. It provides an anti-decoherence quantum state encoding method and its quantum computing system based on the symmetry of an isosceles trapezoidal address array. The method simultaneously maps the amplitude and phase of the quantum state to the geometric structure of the address array, and utilizes the symmetry and conservation properties of the address array to preserve the complete information of the quantum state. The phase lost during decoherence can be reconstructed from the symmetry constraints of the address position. (I) This invention provides a decoherent quantum state encoding method based on the symmetry of an isosceles trapezoidal address array, comprising the following steps: Step 1: Obtain the superposition state of the qubit and extract the amplitude and phase information. Step 2: Encode the amplitude information into a first address number in the first address space, and encode the phase information into a second address number in the second address space. The first address number and the second address number together form an address pair. Step 3: Calculate the cardinality difference between the first address space and the second address space, and apply address pruning constraints: retain address pairs whose absolute value of the difference between the first address number and the second address number does not exceed the cardinality difference, and limit the retained address pairs to an isosceles trapezoidal address array, wherein the address array is symmetrical about the central axis of symmetry. Step 4: Encode the phase information as the offset of the address pair relative to the central axis of symmetry. Different offsets correspond to different phase values, and there is a one-to-one correspondence between the offset and the phase value. Encode the amplitude information as the layer position of the address pair in the address array. Step 5: Quantum gate operations are implemented in the address array as address pair rearrangement operations, with each input address pair uniquely corresponding to an output address pair. Step 6: When decoherence causes address pairs to drift, reconstruct the original phase information by searching for the nearest valid layer to the current address pair. (ii) The present invention also provides a decoherent quantum state coding system based on the symmetry of an isosceles trapezoidal address array, comprising: A quantum state acquisition unit is used to acquire the superposition state of the qubit and extract amplitude and phase information. An address mapping unit, connected to the quantum state acquisition unit, is used to encode the amplitude information as a first address number and the phase information as a second address number. A pruning constraint unit, connected to the address mapping unit, is used to apply address pruning constraints to generate an isosceles trapezoidal address array. A rearrangement operation unit, connected to the pruning constraint unit, is used to perform address pair rearrangement operations corresponding to quantum gates in the address array. A phase reconstruction unit, connected to the rearrangement operation unit, is used to reconstruct the original phase information from the address pair positions. A closed-loop feedback control unit, connected to the phase reconstruction unit, is used to monitor address pair offsets and provide feedback to correct the qubit control parameters. (III) The present invention has the following beneficial effects: (1) Compared with the existing anti-decoherence schemes that only utilize geometric phase and fail to preserve the complete information of the quantum state, the present invention maps the amplitude and phase of the quantum state to the geometric structure of the address array at the same time, and the phase lost due to decoherence can be reconstructed from the symmetry constraints. (2) Compared with the existing quantum error correction codes that require a large amount of physical bit redundancy, the present invention uses the symmetry of the isosceles trapezoidal address array to achieve redundant coding without the need to add additional physical qubits. (3) Compared with the existing quantum gate operations that suffer from information loss due to projection degeneracy, the address pair rearrangement operation corresponding to the quantum gate in the present invention is one-to-one, and each input uniquely corresponds to one output. (4) The closed-loop feedback control unit monitors and corrects the address pair offset in real time, which is expected to effectively suppress the decoherence effect and extend the coherence time. (5) It is compatible with multiple hardware platforms such as superconducting qubits, ion trap qubits, and photonic qubits. Detailed Implementation
[0004] Example 1: Phase-preserving encoding of superconducting qubits. This embodiment applies the encoding method of the present invention to the phase preservation of superconducting qubits. S1. Quantum State Acquisition. Acquire the superposition state of the superconducting qubit, which has a pre-defined amplitude ratio and phase value. S2. Address Mapping. Set the encoding precision parameters, map the amplitude information to a first address number, and map the phase information to a second address number, forming address pairs. Calculate the radix difference between the first address space and the second address space. S3. Clipping Constraint. An address clipping constraint is applied, retaining address pairs that meet the clipping conditions and confining them within an isosceles trapezoidal address array. Phase information is encoded as the offset of the address pair relative to the central axis of symmetry of the address array. S4. Decoherence Simulation. In a noisy environment, the quantum state phase drifts, and the address pairs move synchronously in the address array. S5. Phase Reconstruction. The system reads the current address pair location, searches for the nearest valid layer, and reconstructs the original phase information. S6. Closed-loop feedback. The feedback control unit adjusts the driving parameters of the qubits, pulling the address pairs back to their initial positions and restoring the phase. Implementation Results: Theoretical analysis shows that, under the same noise conditions, the coherence time of the qubit can be extended by several times compared with the uncoded scheme after adopting the encoding method of the present invention, and the phase drift caused by decoherence can be effectively suppressed and reconstructed. Example 2: Verification of the superposition state fidelity of ion trap qubits. This embodiment applies the encoding method of the present invention to the superposition state fidelity verification of ion trap qubits. S1, Quantum State Encoding. The superposition states of the ion trap qubits are mapped onto an isosceles trapezoidal address array. S2, Quantum Gate Operations. This involves rearranging the address pairs corresponding to Hadamard gates and phase gates within the address array. S3. Fidelity Measurement. The fidelity of superposition states is measured using quantum state tomography. Implementation Results: Theoretical analysis shows that, after adopting the encoding method of this invention, the fidelity of quantum gates is expected to be significantly improved, the standard deviation of repeated experiments is expected to be significantly reduced, and the reconstruction accuracy of quantum state tomography is higher than that of the scheme that directly executes quantum gates. Example 3: Synergy with macroscopic quantum teleportation systems. This embodiment integrates the encoding method of the present invention into a macroscopic quantum teleportation system. S1. Encoding Integration. Before quantum state transmission, the quantum state to be transmitted is mapped onto an isosceles trapezoidal address array for encoding. S2. Transmission Preservation. During transmission, the phase information of the quantum state is encoded as the offset of the address pair relative to the central symmetry axis. Even if phase noise is introduced by the transmission channel, the structural information of the address pair can still be identified. S3. Receiver Reconstruction. The receiver reconstructs the complete quantum state information by reading the positions of the address pairs in the isosceles trapezoidal address array. Implementation Results: Theoretical analysis shows that by adopting the encoding preservation method of this invention, the fidelity of macroscopic quantum teleportation can be significantly improved, and the fidelity loss caused by phase noise in direct transmission can be effectively suppressed. Example 4: Hardware implementation of an FPGA-based encoding system. This embodiment demonstrates the implementation and verification of the encoding system of the present invention on an FPGA. S1. Hardware Architecture. The encoding system is implemented on an FPGA, and the address array storage is instantiated using Block RAM. S2. Parallel processing. The pruning judgment and layer statistics are implemented using parallel logic, and each address pair can be processed simultaneously. S3. Performance Evaluation. The encoding system can complete the encoding mapping and phase reconstruction of quantum states within nanosecond to microsecond time, meeting the requirements of real-time quantum control. Attached Figure Description
[0005] Figure 1 This is a block diagram of the overall architecture of the anti-decoherence quantum state coding system based on the symmetry of the isosceles trapezoidal address array of the present invention. Figure 2 A schematic diagram of quantum state mapping to an isosceles trapezoidal address array. Figure 3This is a schematic diagram of the address pair rearrangement operation corresponding to the quantum gate operation in the address array. Figure 4 This is a flowchart of phase information reconstruction and closed-loop feedback control. Terminology Explanation
[0006] Decoherence: The process by which the interaction between a quantum system and its environment leads to the loss of quantum state coherence (especially phase information) over time. Isosceles trapezoidal address array: A discrete address array generated by applying pruning constraints to the first and second address spaces, which has left-right symmetry and a hierarchical structure. Address pair: The combination of the first address number and the second address number uniquely corresponds to an amplitude-phase combination relationship. Legal layer: In an isosceles trapezoidal address array, the set of address pairs with the same "first address number + second address number" value. Offset: The difference between the first address number and the second address number in the address pair, used to encode phase information. Different offsets correspond to different phase values.
Claims
1. A decoherent quantum state encoding method based on the symmetry of an isosceles trapezoidal address array, characterized in that, Includes the following steps: Obtain the superposition state of qubits and extract amplitude and phase information; The amplitude information is encoded as the first address number in the first address space, and the phase information is encoded as the second address number in the second address space. The first address number and the second address number together constitute an address pair. Calculate the cardinality difference between the first address space and the second address space, and apply address pruning constraints: retain address pairs whose absolute value of the difference between the first address number and the second address number does not exceed the cardinality difference, and limit the retained address pairs to an isosceles trapezoidal address array; Phase information is encoded as the offset of address pairs relative to the central axis of symmetry of the address array, with different offsets corresponding to different phase values; Quantum gate operations are implemented as address pair rearrangements in an address array; When decoherence causes address pairs to drift, the original phase information is reconstructed by searching for the nearest valid layer to the current address pair.
2. The method according to claim 1, characterized in that: The offset and the phase value are in one-to-one correspondence, and different offsets correspond to different phase values.
3. The method according to claim 1, characterized in that: The isosceles trapezoidal address array satisfies the conservation of the total number of address pairs, and the total number of address pairs remains unchanged before and after pruning.
4. The method according to claim 1, characterized in that: In the address pair rearrangement operation, the Hadamard gate corresponds to the operation of swapping the first address number and the second address number in the address pair, and the phase gate corresponds to the operation of synchronously shifting the address pair within its respective layer.
5. The method according to claim 1, characterized in that: The phase reconstruction step includes: Read the current address to the position; Search for the nearest valid layer to the current address; Find the nearest address pair on this layer; The reconstructed phase value is calculated based on the offset of this address relative to the central axis of symmetry.
6. A decoherent quantum state encoding system based on the symmetry of an isosceles trapezoidal address array, characterized in that, include: The quantum state acquisition unit is used to acquire the superposition state of the qubit and extract amplitude and phase information; The address mapping unit is connected to the quantum state acquisition unit and is used to encode the amplitude information as a first address number and the phase information as a second address number. A clipping constraint unit, connected to the address mapping unit, is used to apply address clipping constraints to generate an isosceles trapezoidal address array; The rearrangement operation unit, connected to the pruning constraint unit, is used to perform address pair rearrangement operations corresponding to quantum gates in the address array; A phase reconstruction unit, connected to the rearrangement operation unit, is used to reconstruct the original phase information from the address pair positions; A closed-loop feedback control unit, connected to the phase reconstruction unit, is used to monitor address pair offset and provide feedback to correct the control parameters of the qubits.
7. The system according to claim 6, characterized in that: The closed-loop feedback control unit monitors the position offset of the address pair in the isosceles trapezoidal address array in real time, calculates the phase drift, and pulls the address pair back to the initial position by adjusting the driving parameters of the qubit.
8. The system according to claim 6, characterized in that: The system is compatible with at least one type of hardware platform, including superconducting qubits, ion trap qubits, or photonic qubits.
9. The system according to claim 6, characterized in that: The system works in conjunction with the macroscopic quantum teleportation system, performing encoding preservation before quantum state transmission and decoding reconstruction at the receiving end.
10. A quantum computing chip, characterized in that: The system includes the decoherent quantum state encoding system according to any one of claims 6-9, wherein the system is integrated into a superconducting quantum processor or an ion trap quantum processor.