Tunneling out of metastable vacuum in a system consisting of two capacitively coupled phase qubits

TL;DR

This paper calculates the tunneling rate from a metastable vacuum in a system of two capacitively coupled phase qubits using advanced instanton techniques, providing a closed-form expression for specific coupling conditions.

Contribution

It introduces a novel calculation of tunneling rates in coupled qubits using a combination of Coleman's instanton method and Banks and Bender's approach, specifically for intermediate coupling.

Findings

Derived a closed-form expression for tunneling rate

Applied instanton techniques to coupled qubits

Analyzed the effect of coupling asymmetry on tunneling

Abstract

Using a powerful combination of Coleman's instanton technique and the method of Banks and Bender, the exponential factor for the zero temperature rate of tunneling out of metastable vacuum in a system of two identical capacitively coupled phase qubits is calculated in closed form to second order in asymmetry parameter for a special case of intermediate coupling C=C_J/2.