Altuntaş Emine, Spielman I B
Joint Quantum Institute, National Institute of Standards and Technology, and University of Maryland, Gaithersburg, Maryland 20899, USA.
Phys Rev Res. 2023;5(2). doi: 10.1103/physrevresearch.5.023185.
Ultracold atoms are an ideal platform for understanding system-reservoir dynamics of many-body systems. Here, we study quantum back-action in atomic Bose-Einstein condensates, weakly interacting with a far-from resonant, i.e., dispersively interacting, probe laser beam. The light scattered by the atoms can be considered as a part of quantum measurement process, whereby the change in the system state derives from measurement back-action. We experimentally quantify the resulting back-action in terms of the deposited energy. We model the interaction of the system and environment with a generalized measurement process, leading to a Markovian reservoir. Further, we identify two systematic sources of heating and loss: a stray optical lattice and probe-induced light-assisted collisions (an intrinsic atomic process). The observed heating and loss rates are larger for blue detuning than for red detuning, where they are oscillatory functions of detuning with increased loss at molecular resonances and reduced loss between molecular resonances.
超冷原子是理解多体系统的系统-库动力学的理想平台。在此，我们研究原子玻色-爱因斯坦凝聚体中的量子反作用，其与远失谐（即色散相互作用）的探测激光束发生弱相互作用。原子散射的光可被视为量子测量过程的一部分，借此系统状态的变化源自测量反作用。我们通过沉积能量对由此产生的反作用进行了实验量化。我们用广义测量过程对系统与环境的相互作用进行建模，从而得到一个马尔可夫库。此外，我们识别出加热和损耗的两个系统性来源：一个杂散光学晶格和探测诱导的光辅助碰撞（一种内在的原子过程）。对于蓝失谐，观察到的加热和损耗率大于红失谐时的情况，在红失谐时它们是失谐的振荡函数，在分子共振处损耗增加，在分子共振之间损耗减小。
