Probing Topological Matter by «Heating»: From Quantized Circular Dichroism to Tensor Monopoles

MPSD Seminar

  • Date: Jan 15, 2019
  • Time: 11:00 AM - 12:00 PM (Local Time Germany)
  • Speaker: Nathan Goldman
  • Université libre de Bruxelles, Dept. Physics of Complex Systems (CENOLI)
  • Location: CFEL (Bldg. 99)
  • Room: Seminar Room I, EG.076
  • Host: Gregor Jotzu / Andrea Cavalleri
The intimate connection between topology and quantum physics has been widely explored in high-energy and solid-state physics, revealing a plethora of remarkable physical phenomena over the years. Building on their universal nature, topological properties are currently studied in an even broader context, ranging from ultracold atomic gases to photonics, where distinct observables and probes offer a novel view on topological quantum matter.

In this talk, I will discuss how the geometry of quantum states can be revealed using a universal scheme based on excitation-rate measurements upon periodic driving [1,2,3]. When applied to Chern insulators or Landau levels, this approach leads to a quantized circular dichroism phenomenon [1,2], which can be interpreted as the dissipative counterpart of the quantum Hall effect. Besides, we will present protocols allowing for the experimental detection of the quantum metric tensor [3,4], which could be applied to detect new forms of monopoles in higher dimensions [5]. Finally, I will report on the first experimental observation of quantized circular dichroism in an ultracold Fermi gas [6], and describe how this scheme can be applied to reveal the topological order of fractional Chern insulators [7].

[1] D. T. Tran, A. Dauphin, A. G. Grushin, P. Zoller and N. Goldman, Science Advances 3, e1701207 (2017).
[2] D. T. Tran, N. R. Cooper, and N. Goldman, Phys. Rev. A 97, 061602(R) (2018).
[3] T. Ozawa and N. Goldman, Phys. Rev. B 97, 201117(R) (2018).
[4] M. Yu, P. Yang, M. Gong, Q. Cao, Q. Lu, H. Liu, M. B. Plenio, F. Jelezko, T. Ozawa, N. Goldman, S. Zhang and J. Cai, arXiv:1811.12840 (2018)
[5] G. Palumbo and N. Goldman, Phys. Rev. Lett. 121, 170401 (2018).
[6] L. Asteria, D. T. Tran, T. Ozawa, M. Tarnowski, B. S. Rem, N. Fläschner, K. Sengstock, N. Goldman and C. Weitenberg, arXiv:1805.11077 (2018).
[7] C. Repellin and N. Goldman, arXiv:1811.08523 (2018).

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