Robustness of Wave Functions of Interacting Many Bosons in a Leaky Box

Abstract

We study the robustness, against the leakage of bosons, of wave functions of interacting many bosons confined in a finite box, by deriving and analyzing a general equation of motion for the reduced density operator. We identify a robust wave function that remains a pure state, whereas other wave functions, such as the Bogoliubov's ground state and the ground state with a fixed number of bosons, evolve into mixed states. Although these states all have the off-diagonal long-range order, and almost the same energy densities, we argue that only the robust state is realized as a macroscopic quantum state.

Minor typographical errors, which are summarized in the Erratum (which has been submitted to PRL), have been fixed

References in corpus (2)

• Symmetry Breaking and Finite Size Effects in Quantum Many-Body Systems
• Time evolution of condensed state of interacting bosons with reduced number fluctuation in a leaky box

Cited by in corpus (8)

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• Stability of quantum states of finite macroscopic systems against classical noises, perturbations from environments, and local measurements
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• Finite-size scaling of the Shannon-Rényi entropy in two-dimensional systems with spontaneously broken continuous symmetry
• Cluster Property and Robustness of Ground States of Interacting Many Bosons
• Conversion of Thermal Equilibrium States into Superpositions of Macroscopically Distinct States
• Energies and collapse times of symmetric and symmetry-breaking states of finite systems with a U(1) symmetry
• Spontaneous symmetry breaking in coupled Bose-Einstein condensates