Marginal Fermi liquid at magnetic quantum criticality from dimensional confinement

TL;DR

This paper uncovers a new magnetic quantum critical point in a 2D antiferromagnet coupled to 3D electrons, exhibiting marginal Fermi liquid behavior with linear resistivity, using quantum Monte Carlo and field theory.

Contribution

It introduces a novel quantum critical point model showing marginal Fermi liquid behavior through combined simulations and theoretical analysis.

Findings

Quantum critical point exhibits marginal Fermi liquid behavior.

Electrical resistivity shows linear temperature dependence at criticality.

Model applicable to Kondo heterostructures.

Abstract

Metallic quantum criticality is frequently discussed as a source for non-Fermi liquid behavior, but controlled theoretical treatments are scarce. Here we identify and study a novel magnetic quantum critical point in a two-dimensional antiferromagnet coupled to a three-dimensional environment of conduction electrons. Using sign-problem-free quantum Monte Carlo simulations and an effective field-theory analysis, we demonstrate that the quantum critical point is characterized by marginal Fermi liquid behavior. In particular, we compute the electrical resistivity for transport across the magnetic layer, which is shown to display a linear temperature dependence at criticality. Experimental realizations in Kondo heterostructures are discussed.