Dynamical Transition of Quantum Vortex-Pair Annihilation in a Bose-Einstein Condensate

Fuente: arXiv
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Main Authors: Kanai, Toshiaki, Zhang, Chuanwei
Format: Preprint
Published: 2024
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author Kanai, Toshiaki
Zhang, Chuanwei
author_facet Kanai, Toshiaki
Zhang, Chuanwei
contents Understanding the elementary mechanism for the dissipation of vortex energy in quantum liquids is one central issue in quantum hydrodynamics, such as quantum turbulence in systems ranging from neutron stars to atomic condensates. In a two-dimensional (2D) Bose-Einstein condensate (BEC) at zero temperature, besides the vortex drift-out process from the boundary, vortex-antivortex pair can annihilate in the bulk, but controversy remains on the number of vortices involved in the annihilation process. We find there exists a dynamical transition from four-body to three-body vortex annihilation processes with the time evolution in a boundary-less uniform quasi-2D BEC. Such dynamical transition depends on the initial vortex pair density, and occurs when the sound waves generated in the vortex annihilation process surpass a critical energy. With the confinement along the third direction is relaxed in a quasi-2D BEC, the critical sound wave energy decreases due to the 3D vortex line curve and reconnection, shifting the dynamical transition to the early time. Our work reveals an elementary mechanism for the dissipation of vortex energy that may help understand exotic matter and dynamics in quantum liquids.
format Preprint
id arxiv_https___arxiv_org_abs_2407_14627
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Dynamical Transition of Quantum Vortex-Pair Annihilation in a Bose-Einstein Condensate
Kanai, Toshiaki
Zhang, Chuanwei
Quantum Gases
Understanding the elementary mechanism for the dissipation of vortex energy in quantum liquids is one central issue in quantum hydrodynamics, such as quantum turbulence in systems ranging from neutron stars to atomic condensates. In a two-dimensional (2D) Bose-Einstein condensate (BEC) at zero temperature, besides the vortex drift-out process from the boundary, vortex-antivortex pair can annihilate in the bulk, but controversy remains on the number of vortices involved in the annihilation process. We find there exists a dynamical transition from four-body to three-body vortex annihilation processes with the time evolution in a boundary-less uniform quasi-2D BEC. Such dynamical transition depends on the initial vortex pair density, and occurs when the sound waves generated in the vortex annihilation process surpass a critical energy. With the confinement along the third direction is relaxed in a quasi-2D BEC, the critical sound wave energy decreases due to the 3D vortex line curve and reconnection, shifting the dynamical transition to the early time. Our work reveals an elementary mechanism for the dissipation of vortex energy that may help understand exotic matter and dynamics in quantum liquids.
title Dynamical Transition of Quantum Vortex-Pair Annihilation in a Bose-Einstein Condensate
topic Quantum Gases
url https://arxiv.org/abs/2407.14627