Intrinsic diamagnetism in the Weyl semimetal TaAs

TL;DR

This study reveals that TaAs, a Weyl semimetal, exhibits intrinsic weak diamagnetism and a temperature-dependent magnetization minimum, indicating the Fermi level is not at the Weyl nodes, consistent with theoretical predictions.

Contribution

The paper provides experimental evidence of intrinsic diamagnetism in TaAs and shows the Fermi level's position relative to Weyl nodes, supporting theoretical models.

Findings

TaAs shows weak diamagnetism at 5 K.

Magnetization exhibits a minimum around 185 K.

No phase transition between 5 K and 400 K.

Abstract

We investigate the magnetic properties of TaAs, a prototype Weyl semimetal. TaAs crystals show weak diamagnetism with magnetic susceptibility of about -7 * 10^{-7} emu/(g*Oe) at 5 K. A general feature is the appearance of a minimum at around 185 K in magnetization measurements as a function of temperature. No phase transition is observed in the temperature range between 5 K and 400 K. The magnetic properties indicate that the intrinsic Fermi level in TaAs is not located at the Weyl nodes, in agreement with the theory prediction.