Current-sensitive Hall effect in a chiral-orbital-current state

TL;DR

This paper reports a novel, current-sensitive Hall effect in a chiral orbital current state of Mn3Si2Te6, featuring unprecedented Hall responses and scaling relations, revealing new physics and potential technological applications.

Contribution

It uncovers a giant, current-sensitive Hall effect in a chiral orbital current state, with unique scaling and Hall angle properties, advancing understanding of transport phenomena in such materials.

Findings

Observation of a sharp, current-sensitive peak in Hall resistivity

Large Hall angle up to 0.15, comparable to highest reported values

Scaling relation sigma_xy ~ sigma_xx^alpha with alpha between 3 and 5

Abstract

Chiral orbital currents (COC) underpin a novel colossal magnetoresistance (CMR) in ferrimagnetic Mn3Si2Te6 [1]. Here we report the Hall effect in the COC state which exhibits the following unprecedented features: (1) A sharp, current-sensitive peak in the magnetic field dependence of the Hall resistivity; (2) An unusually large Hall angle reaching up to 0.15 (comparable to the highest values yet reported); and (3) A current-sensitive scaling relation between the Hall conductivity sigma_xy and the longitudinal conductivity sigma_xx, namely, sigma_xy ~ sigma_xx^alpha with alpha ranging between 3 and 5, which is both sensitive to external current and exceptionally large compared to alpha < 2 typical of most solids. These anomalies point to a giant, current-sensitive Hall effect that is unique to the COC state. We argue that a magnetic field induced by the fully developed COC combines with the applied magnetic field to exert the greatly enhanced transverse force on charge carriers, which dictates the novel Hall responses. The COC Hall effect is unique, as it is generated and controlled via the interaction between intrinsic COC and applied external currents, which leads to novel transport phenomena of fundamental and technological significance and requires new physics for explanation.