Fluctuating and dissipative dynamics of dark solitons in quasicondensates
Fluctuating and dissipative dynamics of dark solitons in quasicondensates
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DOI：
10.1103/physreva.84.043640
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发表时间：
2011-07
影响因子：
2.9
通讯作者：
S. P. Cockburn;H. Nistazakis;T. Horikis;P. Kevrekidis;N. Proukakis;D. Frantzeskakis
中科院分区：
文献类型：
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作者：
S. P. Cockburn;H. Nistazakis;T. Horikis;P. Kevrekidis;N. Proukakis;D. Frantzeskakis
本文用数值方法和解析方法研究了谐波捕获、部分凝聚玻色气体中物质波暗孤子的波动和耗散动力学。随机Gross-Pitaevskii方程正确地解释了有限温度下的密度和相位波动，揭示了暗孤子衰变时间在每个温度下都是对数正态分布的，从而表征了先前预测的在每个数值实现系综内的长寿命孤子轨迹[S]。P. Cockburn等人，物理学。生态学报，2004,17(1)。从这些分布中提取的平均孤子寿命的期望值与基于耗散的Gross-Pitaevskii模型（具有相同的从头计算阻尼）的数值和解析预测非常吻合。探索0.8 k{下标B}T<{mu}<1.6 k{下标B}T的状态，我们发现平均孤子寿命随温度的比例为{tau}{约}T{sup -4}，与先前对低温状态k{下标B}T<<{mu}的预测一致。该模型还显示了由于背景波动的存在而引起的振荡孤子可见性的实验相关下降。
The fluctuating and dissipative dynamics of matter-wave dark solitons within harmonically trapped, partially condensed Bose gases is studied both numerically and analytically. A study of the stochastic Gross-Pitaevskii equation, which correctly accounts for density and phase fluctuations at finite temperatures, reveals dark-soliton decay times to be lognormally distributed at each temperature, thereby characterizing the previously predicted long-lived soliton trajectories within each ensemble of numerical realizations [S. P. Cockburn et al., Phys. Rev. Lett. 104, 174101 (2010)]. Expectation values for the average soliton lifetimes extracted from these distributions are found to agree well with both numerical and analytic predictions based upon the dissipative Gross-Pitaevskii model (with the same ab initio damping). Probing the regime for which 0.8 k{sub B}T<{mu}<1.6 k{sub B}T, we find average soliton lifetimes to scale with temperature as {tau}{approx}T{sup -4}, in agreement with predictions previously made for the low-temperature regime k{sub B}T<<{mu}. The model is also shown to capture the experimentally relevant decrease in the visibility of an oscillating soliton due to the presence of background fluctuations.