Ryu C, Samson E C, Boshier M G
Physics Division, Los Alamos National Laboratory, Los Alamos, NM, USA.
Department of Physics, Miami University, Oxford, OH, USA.
Nat Commun. 2020 Jul 3;11(1):3338. doi: 10.1038/s41467-020-17185-6.
Quantum interference of currents is the most important and well known quantum phenomenon in a conventional superconducting quantum interference device (SQUID). Here, we report the observation of quantum interference of currents in an atomtronic SQUID. Analogous to a conventional SQUID, currents flowing through two junctions in an atomtronic SQUID interfere due to the phase difference from rotation. This interference results in modulation of critical currents. This modulation was observed for three different radii with clear modulation periods which were measured to be consistent with fundamental rotation rates. This observation shows the possibility of studying various interesting SQUID physics with an atomtronic SQUID and especially, macroscopic quantum phenomena with currents may be realized with an atomtronic SQUID toward the goal of quantum metrology of rotation sensing.
在传统超导量子干涉器件（SQUID）中，电流的量子干涉是最重要且最为人熟知的量子现象。在此，我们报告在原子超流干涉仪（atomtronic SQUID）中对电流量子干涉的观测结果。与传统SQUID类似，流经原子超流干涉仪中两个结的电流由于旋转产生的相位差而发生干涉。这种干涉导致临界电流的调制。对于三种不同半径，均观测到了这种调制，其具有清晰的调制周期，经测量这些周期与基本旋转速率一致。这一观测结果表明，利用原子超流干涉仪研究各种有趣的SQUID物理现象是可能的，特别是朝着旋转传感量子计量的目标，利用原子超流干涉仪可能实现电流相关的宏观量子现象。
