Direct probe of topological order for cold atoms
Abstract
Cold-atom experiments in optical lattices offer a versatile platform to realize various topological quantum phases. A key challenge in those experiments is to unambiguously probe the topological order. We propose a method to directly measure the characteristic topological invariants (order) based on the time-of-flight imaging of cold atoms. The method is generally applicable to detection of topological band insulators in one, two, or three dimensions characterized by integer topological invariants. Using detection of the Chern number for the two-dimensional anomalous quantum Hall states and the Chern-Simons term for the three-dimensional chiral topological insulators as examples, we show that the proposed detection method is practical, and robust to typical experimental imperfections such as limited imaging resolution, inhomogeneous trapping potential, and disorder in the system.
- Publication:
-
Physical Review A
- Pub Date:
- October 2014
- DOI:
- 10.1103/PhysRevA.90.041601
- arXiv:
- arXiv:1407.1146
- Bibcode:
- 2014PhRvA..90d1601D
- Keywords:
-
- 67.85.-d;
- 03.65.Vf;
- 37.10.Jk;
- Ultracold gases trapped gases;
- Phases: geometric;
- dynamic or topological;
- Atoms in optical lattices;
- Condensed Matter - Quantum Gases;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Quantum Physics
- E-Print:
- 10 pages, 5 figures, including Supplemental Material, version accepted by PRA as a Rapid Communication