High-fidelity CNOT gate for spin qubits with asymmetric driving using virtual gates

TL;DR

This paper proposes an asymmetric driving method using virtual gates to significantly improve the fidelity of CNOT gates in spin qubits, addressing off-resonant driving limitations and reducing crosstalk for scalable quantum computing.

Contribution

It introduces a novel asymmetric driving technique with virtual gates to enhance CNOT fidelity and suppress crosstalk in spin qubit systems.

Findings

Fidelity improved by several orders of magnitude.

Virtual gate model enables high-fidelity CNOT operations.

Reduces crosstalk in larger qubit arrays.

Abstract

Recent experiments have demonstrated two-qubit fidelities above 99%, however, theoretically, the fidelity of CNOT operations is limited by off-resonant driving described by off-diagonal terms in the system Hamiltonian. Here we investigate these off-diagonal contributions and we propose a fidelity improvement of several orders of magnitude by using asymmetric driving. Therefore, we provide a description of an ac virtual gate based on a simple capacitance model which not only enables a high fidelity CNOT but also crosstalk reduction when scaling up spin qubit devices to larger arrays.