SAMOP 2021 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 6: Quantum Gases and Matter Waves (joint session Q/A)

Q 6.8: Poster

Tuesday, September 21, 2021, 16:30–18:30, P

Bound Pairs Scattering off a Floquet Driven Impurity — •Friedrich Hübner, Ameneh Sheikhan, and Corinna Kollath — HISKP, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany

We study how bound pairs of Fermions in a Fermi-Hubbard chain scatter off a driven impurity which is a single site with a shaken chemical potential. We thereby extend the work of Thuberg et al. [1] who considered non-interacting single particles.

In the limit where the hopping parameter J is much smaller than the Hubbard interaction U – as long as U is not an integer multiple of the driving frequency ω – we can derive an effective Hamiltonian governing the motions of pairs by means of a Floquet-Schrieffer-Wolff transformation. From it we calculate the pair transmission through the impurity and compare it to the single particle transmission. We validate the result by exact diagonalization and find that it is still a good approximation for finite J/|U| throughout the non-resonant case.

We also analytically study the resonant case where U is an integer multiple of ω which leads to pair breaking by absorbing energy from the drive. Contrary to our expectation we find that pair breaking is suppressed for J ≪ |U|.

[1] D. Thuberg, S. Reyes, S. Eggert, PhysRevB.93.180301 (2016)