Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Sci Adv. 2017 Apr 21;3(4):e1602685. doi: 10.1126/sciadv.1602685. eCollection 2017 Apr.
The prospect of studying topological matter with the precision and control of atomic physics has driven the development of many techniques for engineering artificial magnetic fields and spin-orbit interactions. Recently, the idea of introducing nontrivial topology through the use of internal (or external) atomic states as effective "synthetic dimensions" has garnered attraction for its versatility and possible immunity from heating. We engineer tunable gauge fields through the local control of tunneling phases in an effective two-dimensional manifold of discrete atomic momentum states. We demonstrate the ability to create homogeneous gauge fields of arbitrary value, directly imaging the site-resolved dynamics of induced chiral currents. Furthermore, we engineer the first inhomogeneous artificial gauge fields for cold atoms, observing the magnetic reflection of atoms incident upon a step-like variation of an artificial vector potential. These results open new possibilities for the study of topological phases and localization phenomena in atomic gases.
通过原子物理学的精度和控制来研究拓扑物质的前景，推动了许多用于工程人工磁场和自旋轨道相互作用的技术的发展。最近，通过使用内部（或外部）原子态作为有效的“合成维度”来引入非平凡拓扑的想法因其多功能性和可能免受加热的影响而引起了关注。我们通过在离散原子动量态的有效二维流形中局部控制隧道相位来设计可调谐的规范场。我们展示了创建任意值的均匀规范场的能力，直接成像感应手征电流的局域分辨动力学。此外，我们设计了冷原子的第一个不均匀人工规范场，观察到原子在人工矢量势的阶跃变化上的磁反射。这些结果为原子气体中拓扑相和局域化现象的研究开辟了新的可能性。
