Relaxation of Rabi Dynamics in a Superconducting Multiple-Qubit Circuit

TL;DR

This paper studies how collective Rabi oscillations in a superconducting multi-qubit circuit are affected by interqubit coupling and inhomogeneity, revealing complex relaxation behaviors relevant for quantum simulation.

Contribution

It provides a detailed numerical analysis of relaxation dynamics in multi-qubit circuits considering environmental effects and fabrication inhomogeneity, highlighting their impact on system coherence.

Findings

Relaxation rate varies non-monotonically with interqubit coupling.

Inhomogeneity accelerates energy relaxation and reduces qubit correlations.

Inhomogeneous circuits serve as test beds for quantum many-body studies.

Abstract

We investigate a superconducting circuit consisting of multiple capacitively-coupled charge qubits. The collective Rabi oscillation of qubits is numerically studied in detail by imitating environmental fluctuations according to the experimental measurement. For the quantum circuit composed of identical qubits, the energy relaxation of the system strongly depends on the interqubit coupling strength. As the qubit-qubit interaction is increased, the system's relaxation rate is enhanced firstly and then significantly reduced. In contrast, the inevitable inhomogeneity caused by the nonideal fabrication always accelerates the collective energy relaxation of the system and weakens the interqubit correlation. However, such an inhomogeneous quantum circuit is an interesting test bed for studying the effect of the system inhomogeneity in quantum many-body simulation.