Observation of the quantum boomerang effect

ORAL

Abstract

A particle in an Anderson-localized system, if launched in any direction, should on average return to its starting point and stay there. Despite the central role played by Anderson localization in the modern understanding of condensed matter, this "quantum boomerang" effect, an essential feature of the localized state, was only recently theoretically predicted and has not previously been observed. We report the experimental observation of the quantum boomerang effect. Using a degenerate gas and a phase-shifted pair of optical lattices, we probe the role of time reversal symmetry breaking, Floquet gauge, and initial state symmetry in supporting or disrupting the boomerang effect. Highlighting the key role of localization, we observe that as stochastic kicking destroys dynamical localization, the quantum boomerang effect also disappears. Measured dynamics are in agreement with analytical and numerical predictions. These results showcase a unique experimental probe of the underlying quantum nature of Anderson localized matter.

*The authors acknowledge support from the AFOSR (FA9550-20-1-0240), the ARO (W911NF-20-1-0294), the NSF (CAREER 1555313), the Eddleman Center for Quantum Innovation, the NSF QLCI program (OMA-2016245), the UCSB NSF Quantum Foundry through the Q-AMASEi program (Grant No. DMR-1906325), CNPq (grant no. 311079/2015-6), and the Serrapilheira Institute (grant number Serra-1812-27802).

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Publication: Sajjad et al., Observation of the quantum boomerang effect (2021), arXiv:2109.00696 [cond-mat.quant-gas]

Presenters

  • Roshan Sajjad

    • University of California, Santa Barbara

Authors

  • Roshan Sajjad

    • University of California, Santa Barbara

  • Jeremy Tanlimco

    • University of California, Santa Barbara

  • Hector Mas

    • University of California, Santa Barbara

  • Alec J Cao

    • University of Cambridge
    • University of California, Santa Barbara

  • Eber Nolasco-Martinez

    • University of California, Santa Barbara

  • Ethan Q Simmons

    • University of California, Santa Barbara

  • Flavio Santos

    • Universidade Federal do Rio Grande do Norte

  • Patrizia Vignolo

    • Universit´e Cˆote d'Azur, CNRS, Institut de Physique de Nice

  • Tommaso Macr`ı

    • Universidade Federal do Rio Grande do Norte

  • David M Weld

    • University of California, Santa Barbara