Quantum interferometry at zero and finite temperature with two-mode bosonic Josephson junctions

TL;DR

This paper investigates phase interferometry with bosonic Josephson junctions, demonstrating sub shot-noise sensitivities at both zero and finite temperatures and deriving a scaling law for system size and temperature.

Contribution

It introduces a phase sensitivity indicator for bosonic Josephson junctions and establishes conditions for sub shot-noise precision at finite temperatures.

Findings

Sub shot-noise phase sensitivities achievable at finite temperature

Scaling law relating system size and temperature for shot-noise limit

Analysis of zero and finite temperature effects on interferometry

Abstract

We analyze phase interferometry realized with a bosonic Josephson junction made of trapped dilute and ultracold atoms. By using a suitable phase sensitivity indicator we study the zero temperature junction states useful to achieve sub shot-noise precisions. Sub shot-noise phase shift sensitivities can be reached even at finite temperature under a suitable choice of the junction state. We infer a scaling law in terms of the size system (that is, the number of particles) for the temperature at which the shot-noise limit is not overcome anymore