Bloch state tomography using Wilson lines
Bloch state tomography using Wilson lines
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DOI：
10.1126/science.aad5812
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发表时间：
2016-05-27
期刊：
影响因子：
56.9
通讯作者：
Schneider, Ulrich
中科院分区：
文献类型：
--
作者：
Li, Tracy;Duca, Lucia;Schneider, Ulrich
拓扑学和几何学对我们理解现代物理学至关重要，它们是高能理论、量子信息和凝聚态物理中许多基本概念的基础。在凝聚态系统中，许多现象都源于能带本征态的几何形状，对于一般的多能带系统，能带本征态被编码为矩阵值-威尔逊线。使用加载在蜂窝光学晶格中的超冷Rb原子气体，我们实现了由Wilson线描述的Bloch带中的强力动力学，并观察到带布居的演化直接揭示了带的几何形状。我们的技术能够完全确定带本征态、Berry曲率和拓扑不变量，包括单带和多带Chern数和Z(2)数。
Topology and geometry are essential to our understanding of modern physics, underlying many foundational concepts from high-energy theories, quantum information, and condensed-matter physics. In condensed-matter systems, a wide range of phenomena stem from the geometry of the band eigenstates, which is encoded in the matrix-valued-Wilson line for general multiband systems. Using an ultracold gas of rubidium atoms loaded in a honeycomb optical lattice, we realize strong-force dynamics in Bloch bands that are described by Wilson lines and observe an evolution in the band populations that directly reveals the band geometry. Our technique enables a full determination of band eigenstates, Berry curvature, and topological invariants, including single-and multiband Chern and Z(2) numbers.