Direct Probe of Topological Invariants Using Bloch Oscillating Quantum Walks

作者：Ramasesh V V^*; Flurin E; Rudner M; Siddiqi I; Yao N Y

来源：Physical Review Letters, 2017, 118(13): 130501.

DOI：10.1103/PhysRevLett.118.130501

The topology of a single-particle band structure plays a fundamental role in understanding a multitude of physical phenomena. Motivated by the connection between quantum walks and such topological band structures, we demonstrate that a simple time-dependent, Bloch-oscillating quantum walk enables the direct measurement of topological invariants. We consider two classes of one-dimensional quantum walks and connect the global phase imprinted on the walker with its refocusing behavior. By disentangling the dynamical and geometric contributions to this phase, we describe a general strategy to measure the topological invariant in these quantum walks. As an example, we propose an experimental protocol in a circuit QED architecture where a superconducting transmon qubit plays the role of the coin, while the quantum walk takes place in the phase space of a cavity.

• 出版日期2017-3-27