Error suppression by a virtual two-qubit gate

Abstract

Sparse connectivity of a superconducting quantum computer results in the large experimental overheads of SWAP gates. In this study, we consider employing a virtual two-qubit gate (VTQG) as an error suppression technique. The VTQG enables a non-local operation between a pair of distant qubits using only single qubit gates and projective measurements. Here, we apply the VTQG to the digital quantum simulation of the transverse-field Ising model on an IBM quantum computer to suppress the errors due to the noisy two-qubit operations. We present an effective use of VTQG, where the reduction of multiple SWAP gates results in increasing the fidelity of the output states. The obtained results indicate that the VTQG can be useful for suppressing the errors due to the additional SWAP gates. Additionally, by combining a pulse-efficient transpilation method with the VTQG, further suppression of the errors is observed. In our experiments, we have observed one order of magnitude improvement in accuracy for the quantum simulation of the transverse-field Ising model with 8 qubits.

5 pages, 6 figures

References in corpus (5)

• Quantum Error Mitigation
• Hybrid quantum-classical algorithms and quantum error mitigation
• CutQC: Using Small Quantum Computers for Large Quantum Circuit Evaluations
• Pulse-efficient quantum machine learning
• Quantum Simulation on Noisy Superconducting Quantum Computers

Cited by in corpus (6)

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• Efficient implementation of discrete-time quantum walks on quantum computers
• Experimental demonstration of a high-fidelity virtual two-qubit gate
• Double-bracket quantum algorithms for quantum imaginary-time evolution
• Single entanglement connection architecture between multi-layer bipartite Hardware Efficient Ansatz
• Role of Riemannian geometry in double-bracket quantum imaginary-time evolution