Macroscopic superpositions in Bose-Josephson junctions: Controlling decoherence due to atom losses

TL;DR

This paper investigates how atom losses impact macroscopic superpositions in Bose-Josephson junctions, identifying conditions to protect quantum coherence for enhanced atom interferometry.

Contribution

It introduces methods to control decoherence in superpositions by tuning energies, extending coherence lifetime despite atom losses.

Findings

Quantum coherence is lost after a single atom loss in symmetric cases.

Proper energy tuning can protect superpositions against multiple losses.

Protected superpositions maintain quantum correlations useful for interferometry.

Abstract

We study how macroscopic superpositions of coherent states produced by the nondissipative dynamics of binary mixtures of ultracold atoms are affected by atom losses. We identify different decoherence scenarios for symmetric or asymmetric loss rates and interaction energies in the two modes. In the symmetric case the quantum coherence in the superposition is lost after a single loss event. By tuning appropriately the energies we show that the superposition can be protected, leading to quantum correlations useful for atom interferometry even after many loss events.