Error correction controlled NOT gate of quantum surface code based on novel quantum bit interaction topology

Abstract

The invention discloses an error correction controlled NOT gate of a quantum surface code based on a novel qubit interaction topology, and the error correction controlled NOT gate is composed of an affiliated logic qubit A, a control logic qubit C and a target logic qubit T. The affiliated logic qubit A is connected with the control logic qubit C and the target logic qubit T, and the control logicqubit C is connected with the target logic qubit T; the affiliated logic qubit A, the control logic qubit C and the target logic qubit T are all X-Z stabilizers based on a second-order honeycomb structure, and the X-Z stabilizers based on the second-order honeycomb structure are used as logic qubits to reduce the number of physical qubits needed by a single logic qubit. Therefore, the number of physical quantum bits of the error correction controlled NOT gate based on the quantum surface code and needing three logic quantum bits is reduced, the implementation cost of the error correction controlled NOT gate based on the quantum surface code is reduced, and similarly, the implementation cost of other error-correctable quantum logic gates of the error correction controlled NOT gate based onthe quantum surface code can be reduced.

Description

technical field [0001] The invention relates to a quantum computer, in particular to an error-correcting controlled NOT gate based on a quantum surface code of a novel qubit interaction topology. Background technique [0002] With the continuous development of quantum computing, its potential or direct subversive impact on many fields has been recognized by more and more scholars. The current real quantum system is called "intermediate-scale noisy quantum computer (NISQ)" because the number of integrated qubits is not large (within 100 qubits) and there are noises such as quantum decoherence that affect the calculation results. Due to the existence of noise, the quantum operation process in the NISQ system is "error-prone", and its errors usually manifest in two aspects: gate error and decoherence. Gate error means that a certain quantum state has a certain probability of outputting as a wrong quantum state result after a certain quantum gate operation, and decoherence mean...

AI Technical Summary

Problems solved by technology

Depending on the boundary, the three logical qubits can be closely or loosely arranged, and the error correction CNOT gate based on the surface code with the three logical qubits closely arranged requires 51 physical qubits, 3 logical The error-correcting CNOT gate based on the surface code with qubits loosely arranged needs 49 physical qubits. The disadvantage of this method is that the number of pairs of the nearest physical qubits in the two-dimensional structure is at most 4 pairs, resulting in The error-correcting CNOT gate of the surface code requires more physical qubits, which leads to a higher cost for the realization of the error-correcting CNOT gate based on the quantum surface code. Similarly, it can be known that other error-correcting methods of the error-correcting CNOT gate based on the quantum surface code Quantum logic gates will also be expensive to implement

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