Robust Flat Magnetoresistivity in D0$_3$-Fe$_3$Ga Driven by Chiral Anomaly

TL;DR

This paper reports the discovery of robust flat magnetoresistance and chiral anomaly effects in D0_3-Fe_3Ga, confirming its topological flat-band semimetal nature and potential for quantum devices.

Contribution

It demonstrates the existence of tilted Weyl points from flat bands and reports unprecedented flat magnetoresistance up to 33 T in D0_3-Fe_3Ga.

Findings

Observation of positive and negative magnetoresistance, PLMR, and PHE.

Pronounced non-Fermi-liquid behavior and giant anomalous Hall conductivity.

Flat magnetoresistance persists without decay up to 33 T.

Abstract

Topologically non-trivial nodes emerging from flat-band crossings not only enhance unconventional topological responses but also play a fundamental role in exploring correlation-driven topological physics. Here, we report the exceptionally robust chiral-anomaly-dominated transport in D0_3-Fe_3Ga. First, we observe a combination of positive and negative magnetoresistance, ideal planar longitudinal magnetoresistance (PLMR), and the planar Hall effect (PHE). Second, ultra-low-temperature resistivity exhibits pronounced non-Fermi-liquid (NFL) behavior, accompanied by the emergence of giant intrinsic anomalous Hall conductivity (AHC), in excellent agreement with our DFT calculations, which confirm the existence of tilted Weyl points arising from crossings of nearly three-dimensional (3D) flat bands. Most remarkably, we detect an exceptionally robust flat magnetoresistance (flat-MR) that persists without decay up to 33 T. This set of phenomena provides strong evidence that the Fermi level intersects the flattened Weyl crossings, offering confirmation of a topological flat-band semimetal. D0_3-Fe_3Ga presents a promising magnetic platform for quantum device innovations.