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arXiv · 1804.06345

Imaging topology of Hofstadter ribbons

Dina Genkina·Lauren M. Aycock·Hsin-I Lu·Alina M. Pineiro·Mingwu Lu·I. B. Spielman
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Abstract

Physical systems with non-trivial topological order find direct applications in metrology[1] and promise future applications in quantum computing[2,3]. The quantum Hall effect derives from transverse conductance, quantized to unprecedented precision in accordance with the system's topology[4]. At magnetic fields beyond the reach of current condensed matter experiment, around 10^4 Tesla, this conductance remains precisely quantized but takes on different values[5]. Hitherto, quantized conductance has only been measured in extended 2-D systems. Here, we engineered and experimentally studied narrow 2-D ribbons, just 3 or 5 sites wide along one direction, using ultracold neutral atoms where such large magnetic fields can be engineered[6-11]. We microscopically imaged the transverse spatial motion underlying the quantized Hall effect. Our measurements identify the topological Chern numbers with typical uncertainty of 5%, and show that although band topology is only properly defined in infinite systems, its signatures are striking even in nearly vanishingly thin systems.

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Dina Genkina, Lauren M. Aycock, Hsin-I Lu, Alina M. Pineiro, Mingwu Lu, I. B. Spielman. 2018-04-18. Imaging topology of Hofstadter ribbons. https://doi.org/10.1088/1367-2630%2Fab165b

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