Orbital Many-Body Dynamics of Bosons in the Second Bloch Band of an Optical Lattice.
Orbital Many-Body Dynamics of Bosons in the Second Bloch Band of an Optical Lattice.
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DOI：
10.1103/physrevlett.126.200402
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发表时间：
2020-08
影响因子：
8.6
通讯作者：
J. Vargas;M. Nuske;R. Eichberger;C. Hippler;L. Mathey;A. Hemmerich
中科院分区：
文献类型：
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作者：
J. Vargas;M. Nuske;R. Eichberger;C. Hippler;L. Mathey;A. Hemmerich
我们探索了铷原子在光学方形晶格的第二个Bloch带中的玻色-爱因斯坦凝聚体的类约瑟夫森动力学，提供了具有两个不相等的简并能量最小值的双阱结构。这种振荡是除了常规的现场碰撞外，预计在该系统中出现的轨道变化碰撞的直接标志。观察到的振荡频率与这些碰撞相互作用的相对强度有关，这可以很容易地通过单元胞的扭曲来调整。将观测结果与两个单粒子模式的量子模型和晶格中12×12管状位置的半经典多波段紧密结合模拟进行了比较。这两个模型都再现了观测到的振荡动力学，并显示了振荡频率与现场和轨道变化碰撞过程强度之比的正确依赖关系。
We explore Josephson-like dynamics of a Bose-Einstein condensate of rubidium atoms in the second Bloch band of an optical square lattice providing a double well structure with two inequivalent, degenerate energy minima. This oscillation is a direct signature of the orbital changing collisions predicted to arise in this system in addition to the conventional on-site collisions. The observed oscillation frequency scales with the relative strength of these collisional interactions, which can be readily tuned via a distortion of the unit cell. The observations are compared to a quantum model of two single-particle modes and to a semiclassical multiband tight-binding simulation of 12×12 tubular sites of the lattice. Both models reproduce the observed oscillatory dynamics and show the correct dependence of the oscillation frequency on the ratio between the strengths of the on-site and orbital changing collision processes.