Coherence lifetimes of excitations in an atomic condensate due to the thin spectrum

TL;DR

This paper investigates the quantum coherence and decoherence times of atomic condensates and their excitations, emphasizing the role of the thin spectrum and temperature effects in determining their lifetimes.

Contribution

It introduces a formalism combining toy-model and thin spectrum approaches to analyze coherence lifetimes in finite atomic condensates at various temperatures.

Findings

Decoherence time for ground state condensate depends on temperature and symmetry breaking.

Lifetimes of Bogoliubov quasi-particles are influenced by the thin spectrum.

Coherence times are contrasted with excitation observability windows.

Abstract

We study the quantum coherence properties of a finite sized atomic condensate using a toy-model and the thin spectrum model formalism. The decoherence time for a condensate in the ground state, nominally taken as a variational symmetry breaking state, is investigated for both zero and finite temperatures. We also consider the lifetimes for Bogoliubov quasi-particle excitations, and contrast them to the observability window determined by the ground state coherence time. The lifetimes are shown to exhibit a general characteristic dependence on the temperature, determined by the thin spectrum accompanying the spontaneous symmetry breaking ground state.