2021/05/04 by Mingxia Huo, Ying Li · 2 citations
Computer Science · Mathematics · Physics and Astronomy · #Algorithm #Computer science #Dual (grammatical number) #Mathematics #Observable #Overhead (engineering) #Physics #Protocol (science) #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum circuit #Quantum computer #Quantum error correction #Quantum mechanics #Quantum state #Qubit #State (computer science) #Topology (electrical circuits) #quant-ph
paper · pdf · doi:10.1103/physreva.105.022427
8 pages, 3 figures
arxiv created 2021/05/04 · openalex publication_date 2022/02/18 · arxiv updated 2022/03/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Quantum error mitigation is essential for computing on the noisy quantum computer with a limited number of qubits. In this paper, we propose a practical protocol of error mitigation by virtually purifying the quantum state without qubit overhead or requiring only one ancillary qubit. In dual-state purification, we effectively generate a purified state with increased fidelity using the erroneous state and its dual state, respectively, prepared with the noisy quantum circuit and the dual map of its inverse circuit. Combined with tomography purification, we can make sure that the final estimate of an observable is obtained from a pure state. The numerical result suggests that our protocol reduces the error by a rescaling factor decreasing with the qubit number and circuit depth, i.e. the performance of purification is better for larger circuits. On a cloud quantum computer, we successfully demonstrate the reduced error with a quantum variational eigensolver circuit.