17-22 July 2022
Royal Conservatory of Music, Toronto
America/Toronto timezone

Transport in the 2D Fermi-Hubbard model: Lessons from weak coupling

19 Jul 2022, 17:00
1h 30m
Hart House (Hart House)

Hart House

Hart House

7 Hart House Cir, Toronto, ON M5S 3H3
Poster presentation Degenerate gases, many-body physics, and quantum simulation Poster session

Description

Recent cold atom experiments have observed bad and strange metal behaviors in strongly-interacting Fermi-Hubbard systems. Motivated by these results, we calculate the thermoelectric transport properties of a 2D Fermi-Hubbard system in the weak coupling limit using quantum kinetic theory. We find that many features attributed to strong correlations are also found at weak coupling. In particular, for temperatures $T>t$ the electrical resistivity is nearly linear in temperature despite the fact that the quasiparticle scattering rate is non-linear and changes by nearly an order of magnitude. We argue that this asymptotic behavior is a general feature of systems with a finite spectral width, which implies that there is no MIR bound on the resistivity in single-band models. Due to nesting, the $T$-linear resistivity persists down to $T=0$ at half filling. Our work sheds light on the transport regimes accessible in ultracold atom experiments, which can differ substantially from that of condensed matter systems. Disentangling these band-structure effects from the physics of strong correlations is a major challenge for future experiments.

Presenter name Thomas Kiely

Primary authors

Thomas Kiely (Cornell University) Dr Erich Mueller (Cornell University)

Presentation Materials

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