Atom number fluctuations in Bose gases—statistical analysis of parameter estimation

IF 1.5 4区物理与天体物理 Q3 OPTICS

Journal of Physics B: Atomic, Molecular and Optical Physics Pub Date : 2024-09-06 DOI:10.1088/1361-6455/ad7458

T Vibel, M B Christensen, R M F Andersen, L N Stokholm, K Pawłowski, K Rzążewski, M A Kristensen, J J Arlt

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引用次数: 0

Abstract

The investigation of atom number fluctuations in quantum gases at finite temperatures showcases the ongoing challenges in understanding complex quantum systems. Recently, the microcanonical nature of atom number fluctuations in weakly interacting Bose–Einstein condensates was observed. This motivates an investigation of the thermal component of partially condensed Bose gases, due to the conservation of the total atom number. Here, we present a combined analysis of both components, including a comprehensive analysis of the uncertainties in the preparation and parameter extraction of partially condensed quantum gases. This enables a complementary observation of the thermal atom number fluctuations and yields and improved value of the peak BEC atom number fluctuations

ΔNp,02=(3.7±7)×105

close to the critical temperature. This corresponds to a reduction by 41% with respect to previous analysis and corroborates the microcanonical nature of the fluctuations. The analysis of noise contributions due to the preparation and evaluation of partially condensed Bose gases is based on Monte Carlo simulations of optical density profiles. Importantly, this allows for an estimation of the technical noise contributions to the atom number and temperature, which is generally applicable in the field of ultracold atoms.

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玻色气体中的原子数波动--参数估计的统计分析

对有限温度下量子气体中原子序数波动的研究，展示了在理解复杂量子系统方面所面临的持续挑战。最近，在弱相互作用的玻色-爱因斯坦凝聚态中观察到了原子数波动的微观规范性质。由于原子总数守恒，这促使我们对部分凝聚玻色气体的热分量进行研究。在这里，我们对这两种成分进行了综合分析，包括对部分凝聚量子气体的制备和参数提取过程中的不确定性进行全面分析。这使得我们能够对热原子数波动进行补充观察，并在临界温度附近得到了 BEC 原子数波动峰值 ΔNp,02=(3.7±7)×105 的改进值。这相当于比以前的分析减少了 41%，并证实了波动的微观规范性。对部分凝聚玻色气体的制备和评估引起的噪声贡献的分析是基于光密度剖面的蒙特卡罗模拟。重要的是，这可以估算出技术噪声对原子序数和温度的贡献，在超冷原子领域普遍适用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Physics B: Atomic, Molecular and Optical Physics 物理-光学

CiteScore

3.60

自引率

6.20%

发文量

182

审稿时长

2.8 months

期刊介绍： Published twice-monthly (24 issues per year), Journal of Physics B: Atomic, Molecular and Optical Physics covers the study of atoms, ions, molecules and clusters, and their structure and interactions with particles, photons or fields. The journal also publishes articles dealing with those aspects of spectroscopy, quantum optics and non-linear optics, laser physics, astrophysics, plasma physics, chemical physics, optical cooling and trapping and other investigations where the objects of study are the elementary atomic, ionic or molecular properties of processes.