QUANTUM INTERFEROMETRY AT ZERO AND FINITE TEMPERATURE WITH TWO-MODE BOSONIC JOSEPHSON JUNCTIONS.

We analyze phase interferometry realized with a bosonic Josephson junction (BJJ) 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. [ABSTRACT FROM AUTHOR]