SYK non Fermi Liquid Correlations in Nanoscopic Quantum Transport

TL;DR

This paper demonstrates that nano-structures with narrow bands and strong electron-electron interactions can exhibit a non-Fermi liquid phase described by the SYK model, with distinctive transport signatures like anomalous power-law conductance.

Contribution

It shows that SYK non-Fermi liquid behavior can occur in nano-structures and identifies specific transport signatures, expanding the potential physical realizations of SYK physics.

Findings

Observation of algebraic $T^{3/2}$ scaling in conductance

Identification of a quantum phase transition between Fermi liquid and non-Fermi liquid phases

Conditions under which SYK non-Fermi liquid behavior can be stabilized in nano-structures

Abstract

Electronic transport in nano-structures, such as long molecules or 2D exfoliated flakes, often goes through a nearly degenerate set of single-particle orbitals. Here we show that in such cases a conspiracy of the narrow band and strong e-e interactions may stabilize a non Fermi liquid phase in the universality class of the complex Sachdev-Ye-Kitaev (SYK) model. Focusing on signatures in quantum transport, we demonstrate the existence of anomalous power laws in the temperature dependent conductance, including algebraic scaling $T^{3/2}$ in the inelastic cotunneling channel, separated from the conventional Fermi liquid $T^2$ scaling via a quantum phase transition. The relatively robust conditions under which these results are obtained indicate that the SYK non Fermi liquid universality class might be not as exotic as previously thought.