Phase diagram of quantum dissipative junctions

TL;DR

This paper explores the phase diagram of quantum dissipative junctions modeled as quantum rotors coupled to a bath, revealing how capacitance, coupling strength, and many-body effects influence their phases through combined Monte-Carlo and analytical methods.

Contribution

It provides the first comprehensive phase diagram of quantum dissipative junctions considering multiple parameters and compares it with related models.

Findings

Identified distinct phases depending on capacitance and coupling

Mapped the influence of many-body effects on phase transitions

Demonstrated the applicability of combined Monte-Carlo and analytical techniques

Abstract

Mesoscopic capacitances, in the quantum regime, are described as a quantum rotor coupled to a dissipative bath. We analyze the phase diagram of this model, as function of the capacitance, the coupling to the bath (that is, the conductance of the device), and the decay of the correlation functions in the bath, i.\ e., the strength of the many body effects within the leads. By combining Monte-Carlo and analytical techniques, we present the full phase diagram. The similarities and differences with other models of quantum junctions are discussed.