# Absence of a dissipative quantum phase transition in Josephson junctions

## TL;DR

This paper demonstrates that Josephson junctions do not undergo a dissipative quantum phase transition to an insulating state when connected to a resistor, clarifying their behavior in dissipative environments.

## Contribution

It provides a comprehensive analysis showing the absence of a dissipative quantum phase transition in Josephson junctions, resolving long-standing modeling ambiguities.

## Key findings

- Josephson junctions do not become insulating at high resistance
- Clarification of the junction's phase behavior in dissipative environments
- Revised understanding of junction-environment interactions

## Abstract

Half a century after its discovery, the Josephson junction has become the most important nonlinear quantum electronic component at our disposal. It has helped reshape the SI system around quantum effects and is used in scores of quantum devices. By itself, the use of Josephson junctions in the volt metrology seems to imply an exquisite understanding of the component in every aspect. Yet, surprisingly, there have been long-standing subtle issues regarding the modeling of the interaction of a junction with its electromagnetic environment. Here, we find that a Josephson junction connected to a resistor does not become insulating beyond a given value of the resistance due to a dissipative quantum phase transition, as is commonly believed. Our work clarifies how this key quantum component behaves in the presence of a dissipative environment and provides a comprehensive and consistent picture, notably regarding the treatment of its phase.