Hall Coefficient and Resistivity in the Doped Bilayer Hubbard Model

TL;DR

This paper uncovers a novel non-Fermi liquid transport behavior in the hole-doped bilayer Hubbard model, characterized by nonmonotonic Hall coefficient and resistivity plateaus, due to interlayer singlet formation and magnetic fluctuations.

Contribution

It introduces the first detailed study of non-Fermi liquid transport in the doped bilayer Hubbard model considering interlayer correlations.

Findings

Hall coefficient shows nonmonotonic temperature dependence with multiple sign reversals.

Resistivity exhibits two plateaus instead of linear behavior.

Transport behaviors are linked to interlayer singlet formation and magnetic fluctuations.

Abstract

Finding and understanding non-Fermi liquid transport behaviors are at the core of condensed matter physics. Most of the existing studies were devoted to the monolayer Hubbard model, which is the simplest model that captures essential features of high-temperature superconductivity. Here we discover a new type of non-Fermi liquid behavior emergent in the hole-doped bilayer Hubbard model, using dynamical mean-field theory with a full consideration of the short-range interlayer electron correlation. We find that at low temperatures, the Hall coefficient has a strong nonmonotonic dependence on temperature, leading to a double or quadruple reversal of its sign depending on the doping level. At the same time, the resistivity exhibits two plateaus rather than linearity in its temperature dependence. We show that these intriguing transport behaviors stem from the formation of coherent interlayer singlets, which scatter off gapped collective modes arising from short-range interlayer antiferromagnetic fluctuations.