NdAlSi: A magnetic Weyl semimetal candidate with rich magnetic phases and atypical transport properties

Abstract

Magnetic Weyl semimetals (MWSMs) have attracted significant attention due to their intriguing physical properties and potential applications in spin-electronic devices. Here we report the characterization of NdAlSi including transport, magnetization, and heat capacity on single crystals, as well as band structure calculation. It is a newly proposed MWSM candidate which breaks both time-reversal and spatial inversion symmetries. A temperature--magnetic field phase diagram is experimentally established. Remarkably, on the angular magnetoresistance, a twofold symmetric sharp peak instead of a smooth variation is observed across the phase boundary between the ferrimagnetic and antiferromagnetic phases. We argue that the tunability of both the electronic structure and magnetic properties in NdAlSi is crucial for realizing such a behavior. Our results indicate that $4f$-electron-based MWSM could provide a unique platform to explore new and intriguing quantum phenomena arising from the interaction between magnetism and electron topology.