Wilson loop and Wilczek-Zee phase from a non-Abelian gauge field
Wilson loop and Wilczek-Zee phase from a non-Abelian gauge field
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DOI：
10.1038/s41534-021-00483-2
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发表时间：
2019-10
影响因子：
7.6
通讯作者：
S. Sugawa;F. Salces-Carcoba;Y. Yue;A. Putra;I. Spielman
中科院分区：
文献类型：
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作者：
S. Sugawa;F. Salces-Carcoba;Y. Yue;A. Putra;I. Spielman
在绝热穿越一个闭环后，量子态可以获得一个称为贝里相位的几何相位，这取决于路径而不是运动速率。Berry相位类似于由电磁矢量势导出的Aharonov-Bohm相位，并且可以用称为Berry连接的阿贝尔规范势来表示。Wilczek和Zee将这一概念扩展到包括非阿贝尔相位-由非阿贝尔规范电位产生的非阿贝尔相位-以与仪表无关的威尔逊环为特征。利用原子玻色-爱因斯坦凝聚，我们量子工程了一个非阿贝尔SU(2)规范场，由位于5维参数空间原点的杨单极子产生。通过缓慢地环绕单极子，我们用威尔逊环来描述威尔切克- zee相位，它取决于环绕路径所包含的立体角：这是斯托克斯定理的推广。这一观测标志着由非阿贝尔点源产生的威尔逊环的观测。
Quantum states can acquire a geometric phase called the Berry phase after adiabatically traversing a closed loop, which depends on the path not the rate of motion. The Berry phase is analogous to the Aharonov–Bohm phase derived from the electromagnetic vector potential, and can be expressed in terms of an Abelian gauge potential called the Berry connection. Wilczek and Zee extended this concept to include non-Abelian phases—characterized by the gauge-independent Wilson loop—resulting from non-Abelian gauge potentials. Using an atomic Bose–Einstein condensate, we quantum-engineered a non-Abelian SU(2) gauge field, generated by a Yang monopole located at the origin of a 5-dimensional parameter space. By slowly encircling the monopole, we characterized the Wilczek–Zee phase in terms of the Wilson loop, that depended on the solid-angle subtended by the encircling path: a generalization of Stokes’ theorem. This observation marks the observation of the Wilson loop resulting from a non-Abelian point source.