Phonon excitations of Floquet-driven superfluids in a tilted optical lattice

Cruickshank, Robbie and Carli, Andrea Di and Mitchell, Matthew and Rooij, Arthur La and Kuhr, Stefan and Creffield, Charles E. and Haller, Elmar (2024) Phonon excitations of Floquet-driven superfluids in a tilted optical lattice. Physical Review Research, 6 (2). 023323. ISSN 2643-1564 (https://doi.org/10.1103/PhysRevResearch.6.023323)

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Abstract

Tilted lattice potentials with periodic driving play a crucial role in the study of artificial gauge fields and topological phases with ultracold quantum gases. However, driving-induced heating and the growth of phonon modes restrict their use for probing interacting many-body states. Here, we experimentally investigate phonon modes and interaction-driven instabilities of superfluids in the lowest band of a shaken optical lattice. We identify stable and unstable parameter regions and provide a general resonance condition. In contrast to the high-frequency approximation of a Floquet description, we use the micromotion of the superfluids to analyze the growth of phonon modes from slow- to fast-driving frequencies. The model describes phonon excitations in both resonantly and nonresonantly driven systems, with or without a tilted potential. Our observations enable the prediction of stable parameter regimes for quantum-simulation experiments aimed at studying driven systems with strong interactions over extended time scales.

ORCID iDs

Cruickshank, Robbie ORCID logoORCID: https://orcid.org/0009-0004-8662-294X, Carli, Andrea Di ORCID logoORCID: https://orcid.org/0000-0003-0377-6886, Mitchell, Matthew, Rooij, Arthur La, Kuhr, Stefan ORCID logoORCID: https://orcid.org/0000-0001-8386-5357, Creffield, Charles E. and Haller, Elmar ORCID logoORCID: https://orcid.org/0000-0002-7951-1721;
  • Item type:Article
    ID code:89768
    Dates:
    Date
    Event
    25 June 2024
    Published
    18 May 2024
    Accepted
    10 January 2024
    Submitted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:28 Jun 2024 08:42
    Last modified:13 Oct 2024 00:52
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/89768
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