Finite-size scaling of the photon-blockade breakdown dissipative quantum phase transition

TL;DR

This paper demonstrates that the telegraph signal observed in the photon-blockade-breakdown regime of a driven, lossy Jaynes--Cummings model acts as a finite-size precursor to a true first-order quantum phase transition in the thermodynamic limit.

Contribution

It constructs a finite-size scaling framework showing the transition becomes macroscopic, confirming the photon-blockade-breakdown as a first-order dissipative quantum phase transition.

Findings

Telegraph signal is a finite-size precursor to a phase transition.

Finite-size scaling leads to a macroscopic telegraph signal.

Photon-blockade-breakdown is classified as a first-order dissipative quantum phase transition.

Abstract

We prove that the observable telegraph signal accompanying the bistability in the photon-blockade-breakdown regime of the driven and lossy Jaynes--Cummings model is the finite-size precursor of what in the thermodynamic limit is a genuine first-order phase transition. We construct a finite-size scaling of the system parameters to a well-defined thermodynamic limit, in which the system remains the same microscopic system, but the telegraph signal becomes macroscopic both in its timescale and intensity. The existence of such a finite-size scaling completes and justifies the classification of the photon-blockade-breakdown effect as a first-order dissipative quantum phase transition.