2015/08/31 by Hsin-I Lu, Max Schemmer, Lauren M. Aycock +3
Physics and Astronomy · #cond-mat.quant-gas
paper · pdf · doi:10.1103/physrevlett.116.200402
published as Phys. Rev. Lett. 116, 200402 (2016) · 5 pages, 4 figures for the main text + supplementary material
arxiv created 2016/04/29 · arxiv updated 2016/05/25
We realized a quantum geometric "charge" pump for a Bose-Einstein condensate (BEC) in the lowest Bloch band of a novel bipartite magnetic lattice. Topological charge pumps in filled bands yield quantized pumping set by the global -- topological -- properties of the bands. In contrast, our geometric charge pump for a BEC occupying just a single crystal momentum state exhibits non-quantized charge pumping set by local -- geometrical -- properties of the band structure. Like topological charge pumps, for each pump cycle we observed an overall displacement (here, not quantized) and a temporal modulation of the atomic wavepacket's position in each unit cell, i.e., the polarization.