Highly Controllable Qubit-Bath Coupling Based on a Sequence of Resonators

TL;DR

This paper proposes a controllable qubit-bath coupling method using a sequence of LC resonators, enhancing ground state initialization and providing a practical alternative to CPW systems for quantum computing.

Contribution

It introduces a lumped-element model for controllable qubit-bath coupling, offering analytical solutions and a mapping to existing CPW systems, facilitating experimental implementation.

Findings

Achieves strong coupling to low-temperature environment

Enables more efficient ground state initialization

Provides analytical solutions for feasible parameters

Abstract

Combating the detrimental effects of noise remains a major challenge in realizing a scalable quantum computer. To help to address this challenge, we introduce a model realizing a controllable qubit-bath coupling using a sequence of LC resonators. The model establishes a strong coupling to a low-temperature environment which enables us to lower the effective qubit temperature making ground state initialization more efficient. The operating principle is similar to that of a recently proposed coplanar-waveguide cavity (CPW) system, for which our work introduces a complementary and convenient experimental realization. The lumped-element model utilized here provides an easily accessible theoretical description. We present analytical solutions for some experimentally feasible parameter regimes and study the control mechanism. Finally, we introduce a mapping between our model and the recent CPW system.