Universal non-linear conductivity near to an itinerant-electron ferromagnetic quantum critical point

TL;DR

This paper investigates the universal non-linear conductivity behavior in itinerant-electron systems near a magnetic quantum critical point, revealing a power-law relationship between current and electric field influenced by critical exponents.

Contribution

It introduces a universal non-linear conductivity scaling law near quantum critical points, linking resistivity and electric field through critical exponents.

Findings

Non-linear resistivity follows a specific power-law dependence on electric field.

Universal behavior is observed for certain geometries near quantum criticality.

Theoretical framework connects thermal and electrical responses via critical exponents.

Abstract

We study the conductivity in itinerant-electron systems near to a magnetic quantum critical point. We show that, for a class of geometries, the universal power-law dependence of resistivity upon temperature may be reflected in a universal non-linear conductivity; when a strong electric field is applied, the resulting current has a universal power-law dependence upon the applied electric field. For a system with thermal equilibrium current proportional to $T^\alpha$ and dynamical exponent $z$, we find a non-linear resistivity proportional to $E^{\frac{z-1}{z(1+\alpha)-1}}$.