Finite Size Scaling Behavior of Dissipative Tunnel Junctions

TL;DR

This paper uses Quantum Monte Carlo simulations to study how dissipative tunnel junctions behave at different temperatures, revealing a quantum phase transition between coherent and incoherent transport in sub-Ohmic cases.

Contribution

It provides the first detailed finite size scaling analysis of dissipative tunnel junctions, confirming a quantum phase transition and matching renormalization group predictions.

Findings

Absence of coherent transport in Ohmic junctions.

Existence of a quantum phase transition in sub-Ohmic junctions.

Critical exponents agree with theoretical predictions.

Abstract

We present the results of a series of Quantum Monte Carlo calculations of the temperature dependent conductance of dissipative non-superconducting tunnel junctions. Finite size scaling methods are used to demonstrate the absence of coherent transport in Ohmic tunnel junctions. However, a quantum phase transition between coherent and incoherent behavior is found in sub-Ohmic tunnel junctions. The critical conductance is found to be temperature independent and the critical exponents, $\nu$ and $\eta$, are found to be in agreement with renormalization group results by Kosterlitz.