Two-qubit gate operations in superconducting circuits with strong coupling and weak anharmonicity

TL;DR

This paper theoretically analyzes two-qubit gate operations in superconducting circuits with strong coupling and weak anharmonicity, identifying parameter regimes for high-fidelity gates.

Contribution

It provides a numerical study of gate fidelity dependence on system parameters in strongly coupled superconducting qubits with weak anharmonicity.

Findings

Identifies parameter regimes for high-fidelity two-qubit gates

Shows the impact of strong coupling on gate performance

Provides guidelines for experimental implementation

Abstract

We investigate theoretically the implementation of two-qubit gates in a system of two coupled superconducting qubits. In particular, we analyze two-qubit gate operations under the condition that the coupling strength is comparable to or even larger than the anharmonicity of the qubits. By numerically solving the time-dependent Schr\"odinger equation, we obtain the dependence of the two-qubit gate fidelity on the system parameters in the case of direct and indirect qubit-qubit coupling. Our numerical results can be used to identify the "safe" parameter regime for experimentally implementing two-qubit gates with high fidelity in these systems.