Scaling the topological transport based on an effective Weyl model

TL;DR

This paper introduces an effective Weyl-band model in temperature scale for topological semimetals, establishing a universal scaling law for transport phenomena and revealing key sign regularities linked to Weyl node chiralities.

Contribution

It develops a simplified Weyl-band model in temperature scale and demonstrates its universal applicability to transport properties in topological semimetals, supported by experimental verification.

Findings

Universal scaling law for Weyl-fermion transport established

Sign regularity of anomalous Hall and Nernst effects linked to Weyl node chirality

Berry-curvature ferrimagnetic structure explains Nernst sign reversal

Abstract

Magnetic topological semimetals are increasingly fueling interests in exotic electronic-thermal physics including thermoelectrics and spintronics. To control the transports of topological carriers in such materials becomes a central issue. However, the topological bands in real materials are normally intricate, leaving obstacles to understand the transports in a physically clear way. Parallel to the renowned effective two-band model in magnetic field scale for semiconductors, here, an effective Weyl-band model in temperature scale was developed with pure Weyl state and a few meaningful parameters for topological semimetals. Based on the model, a universal scaling was established and subsequently verified by reported experimental transports. The essential sign regularity of anomalous Hall and Nernst transports was revealed with connection to chiralities of Weyl nodes and carrier types. Upon a double-Weyl model, a concept of Berry-curvature ferrimagnetic structure, as an analogy to the real-space magnetic structure, was further proposed and well described the emerging sign reversal of Nernst thermoelectric transports in temperature scale. Our study offers a convenient tool for scaling the Weyl-fermion-related transport physics, and promotes the modulations and applications of magnetic topological materials in future topological quantum devices.