{"title":"Frequency beating and damping of breathing oscillations of a harmonically trapped one-dimensional quasicondensate","authors":"F. A. Bayocboc, Jr., K. Kheruntsyan","doi":"10.5802/crphys.131","DOIUrl":null,"url":null,"abstract":"We study the breathing (monopole) oscillations and their damping in a harmonically trapped one-dimensional (1D) Bose gas in the quasicondensate regime using a finite-temperature classical field approach. By characterising the oscillations via the dynamics of the density profile's rms width over long time, we find that the rms width displays beating of two distinct frequencies. This means that 1D Bose gas oscillates not at a single breathing mode frequency, as found in previous studies, but as a superposition of two distinct breathing modes, one oscillating at frequency close to $\\simeq\\!\\sqrt{3}\\omega$ and the other at $\\simeq\\!2\\omega$, where $\\omega$ is the trap frequency. The breathing mode at $\\sim\\!\\sqrt{3}\\omega$ dominates the beating at lower temperatures, deep in the quasicondensate regime, and can be attributed to the oscillations of the bulk of the density distribution comprised of particles populating low-energy, highly-occupied states. The breathing mode at $\\simeq\\!2\\omega$, on the other hand, dominates the beating at higher temperatures, close to the nearly ideal, degenerate Bose gas regime, and is attributed to the oscillations of the tails of the density distribution comprised of thermal particles in higher energy states. The two breathing modes have distinct damping rates, with the damping rate of the bulk component being approximately four times larger than that of the tails component.","PeriodicalId":50650,"journal":{"name":"Comptes Rendus Physique","volume":" ","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comptes Rendus Physique","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.5802/crphys.131","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 4
Abstract
We study the breathing (monopole) oscillations and their damping in a harmonically trapped one-dimensional (1D) Bose gas in the quasicondensate regime using a finite-temperature classical field approach. By characterising the oscillations via the dynamics of the density profile's rms width over long time, we find that the rms width displays beating of two distinct frequencies. This means that 1D Bose gas oscillates not at a single breathing mode frequency, as found in previous studies, but as a superposition of two distinct breathing modes, one oscillating at frequency close to $\simeq\!\sqrt{3}\omega$ and the other at $\simeq\!2\omega$, where $\omega$ is the trap frequency. The breathing mode at $\sim\!\sqrt{3}\omega$ dominates the beating at lower temperatures, deep in the quasicondensate regime, and can be attributed to the oscillations of the bulk of the density distribution comprised of particles populating low-energy, highly-occupied states. The breathing mode at $\simeq\!2\omega$, on the other hand, dominates the beating at higher temperatures, close to the nearly ideal, degenerate Bose gas regime, and is attributed to the oscillations of the tails of the density distribution comprised of thermal particles in higher energy states. The two breathing modes have distinct damping rates, with the damping rate of the bulk component being approximately four times larger than that of the tails component.
期刊介绍:
The Comptes Rendus - Physique are an open acess and peer-reviewed electronic scientific journal publishing original research article. It is one of seven journals published by the Académie des sciences.
Its objective is to enable researchers to quickly share their work with the international scientific community.
The Comptes Rendus - Physique also publish journal articles, thematic issues and articles on the history of the Académie des sciences and its current scientific activity.
From 2020 onwards, the journal''s policy is based on a diamond open access model: no fees are charged to authors to publish or to readers to access articles. Thus, articles are accessible immediately, free of charge and permanently after publication.
The Comptes Rendus - Physique (8 issues per year) cover all fields of physics and astrophysics and propose dossiers. Thanks to this formula, readers of physics and astrophysics will find, in each issue, the presentation of a subject in particularly rapid development. The authors are chosen from among the most active researchers in the field and each file is coordinated by a guest editor, ensuring that the most recent and significant results are taken into account. In order to preserve the historical purpose of the Comptes Rendus, these issues also leave room for the usual notes and clarifications. The articles are written mainly in English.