Growth dynamics of a Bose-Einstein condensate in a dimple trap without cooling
Michael C. Garrett, Adrian Ratnapala, Eikbert D. van Ooijen, Christopher J. Vale, Kristian Weegink, Sebastian K. Schnelle, Otto Vainio, Norman R. Heckenberg, Ha… 展开作者
Michael C. Garrett, Adrian Ratnapala, Eikbert D. van Ooijen, Christopher J. Vale, Kristian Weegink, Sebastian K. Schnelle, Otto Vainio, Norman R. Heckenberg, Halina Rubinsztein-Dunlop, Matthew J. Davis
备注：
v1: 9 pages, 7 figures, submitted to Phys. Rev. A; v2: 10 pages, 8 figures, fixed typos, added references, additional details on experimental procedure, values of phase-space density, new figure and discussion on effects of three-body loss in Appendix B (replaced with published version)
We study the formation of a Bose-Einstein condensate in a cigar-shaped three-dimensional harmonic trap, induced by the controlled addition of an attractive "dimple" potential along the weak axis. In this manner we are able to induce condensation without cooling due to a localized increase in the phase space density. We perform a quantitative analysis of the thermodynamic transformation in both the sudden and adiabatic regimes for a range of dimple widths and depths. We find good agreement with equilibrium calculations based on self-consistent semiclassical Hartree-Fock theory describing the condensate and thermal cloud. We observe there is an optimal dimple depth that results in a maximum in the condensate fraction. We also study the non-equilibrium dynamics of condensate formation in the sudden turn-on regime, finding good agreement for the observed time dependence of the condensate fraction with calculations based on quantum kinetic theory.
Dynamics of repeated BEC formation and extraction in dimple traps
Taras Shevchenko National University of Kyiv（基辅塔拉斯舍甫琴科国立大学）；Technische Universität Darmstadt（达姆施塔特工业大学）；Georgia Southern University（佐治亚南方大学）；Universitá di Padova（帕多瓦大学）；INFN, Sezione di Padova（意大利国家核物理研究所帕多瓦分部）；GSI Helmholtzzentrum für Schwerionenforschung（德国重离子研究中心）
Accelerating evaporative cooling of a strongly interacting Fermi gas by tilting the optical trap with a magnetic field gradient
School of Physics and Astronomy, Sun Yat-sen University（中山大学物理学院）；Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing, Sun Yat-Sen University（中山大学广东省量子计量与传感重点实验室）；Shenzhen Research Institute of Sun Yat-Sen University（中山大学深圳研究院）；State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University（中山大学光电材料与技术国家重点实验室）
将一氟化钙（CaF）分子装入光偶极阱（ODT）中，随后在阱内进行激光冷却。从磁光捕获开始，我们亚多普勒冷却CaF，然后将$150(30)$ CaF分子加载到ODT中。当亚多普勒冷却光和捕获光同时打开时，获得了五倍的增强负载。对于捕获的分子，我们直接观察到有效的亚多普勒冷却到$60(5)$ $μ\text{K}$的温度。$8(2)\times10^7$ cm $^{-3}$的捕获分子密度比初始亚多普勒冷却样品大一个数量级。750（40）ms的陷阱寿命主要是由背景气体碰撞。
Modeling near ground-state cooling of two-dimensional ion crystals in a Penning trap using electromagnetically induced transparency
潘宁陷阱，具有控制数十到数百个离子的平面晶体的能力，是多功能的量子模拟器。横向于离子晶体平面的运动鼓面模式的热占据降低了量子模拟的质量。利用电磁感应透明的激光冷却（EIT冷却）作为一种快速将鼓面模初始化到接近基态占据的有效方法是有吸引力的。我们数值研究的效率EIT冷却平面离子晶体中的潘宁陷阱，占所产生的复杂性的陷阱的性质和从同时冷却的多个离子。我们表明，尽管面临挑战，鼓面模式（数百千赫）的大带宽可以迅速冷却到近基态职业在几百微秒。我们的预测的质量中心模式包括几十微秒的冷却时间常数和增强的冷却速率与离子的数量增加。NIST潘宁阱中EIT冷却的成功实验演示[E. Jordan，K. A. Gilmore，A. Shankar，A. Safavi-Naini，M. J. Holland和J. J. Bollinger，“近基态冷却的二维捕获离子晶体超过100个离子”，（2018），提交。验证我们的预测。
