Bad metallic transport in a cold atom Fermi-Hubbard system
Abstract
Charge transport is a revealing probe of the quantum properties of materials. Strong interactions can blur charge carriers resulting in a poorly understood "quantum soup". Here we study the conductivity of the Fermi-Hubbard model, a testing ground for strong interaction physics, in a clean quantum system - ultracold Li in a 2D optical lattice. We determine the charge diffusion constant in our system by measuring the relaxation of an imposed density modulation and modeling its decay hydrodynamically. The diffusion constant is converted to a resistivity, which exhibits a linear temperature dependence and exceeds the Mott-Ioffe-Regel limit, two characteristic signatures of a bad metal. The techniques we develop here may be applied to measurements of other transport quantities, including the optical conductivity and thermopower.
Keywords
Cite
@article{arxiv.1802.09456,
title = {Bad metallic transport in a cold atom Fermi-Hubbard system},
author = {Peter T. Brown and Debayan Mitra and Elmer Guardado-Sanchez and Reza Nourafkan and Alexis Reymbaut and Charles-David Hébert and Simon Bergeron and A. -M. S. Tremblay and Jure Kokalj and David A. Huse and Peter Schauss and Waseem S. Bakr},
journal= {arXiv preprint arXiv:1802.09456},
year = {2019}
}