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TT: Fachverband Tiefe Temperaturen
TT 50: Superconductivity: Theory II
TT 50.1: Talk
Wednesday, March 20, 2024, 15:00–15:15, H 3005
Floquet engineering Higgs dynamics in superconductors — •Tobias Kuhn1, Björn Sothmann2, and Jorge Cayao3 — 1Institute of Physics, University of Augsburg, D-86135 Augsburg, Germany — 2Department of Physics, University of Duisburg-Essen and CENIDE, D-47048 Duisburg, Germany — 3Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala, Sweden
The order parameter Δ of periodically driven superconductors with frequency Ω shows spontaneous symmetry breaking analogue to Higgs mechanism [1]. The resulting Higgs mode can be resonantly excited in subgap regime at Ω=Δ through non-linear coupling to light [2]. We develop a Floquet approach to study Higgs dynamics captured by anomalous Floquet Green’s functions. This description exploits the drives periodicity to considerably reduce the complexity of the time-dependent problem [3]. Interestingly, the Floquet approach naturally offers a physical explanation for the renormalized steady state order parameter as a result of photon processes between Floquet subbands. As an example, we demonstrate Floquet engineering Higgs modes in time-periodic s-wave superconductors. Notably, the theory can easily be extended to spin-triplet superconductors and complex interactions as well.
[1] R. Shimano, N. Tsuji, Annu. Rev. Condens. Matter Phys. 11 (2020) 103
[2] N. Tsuji, H. Aoki, Phys. Rev. B 92 (2015) 064508
[3] J. Cayao, C. Triola, A. M. Black-Schaffer, Phys. Rev. B 103, 104505 (2021).
Keywords: Floquet engineering; Higgs dynamics; Periodically driven systems; Non-equilibrium steady states; Theory on superconductivity