Quantum oscillations in Noncentrosymmetric Weyl semimetals RAlSi (R = Sm and Ce)

TL;DR

This study investigates the structural, magnetic, and transport properties of noncentrosymmetric RAlSi (R=Sm, Ce) Weyl semimetals, revealing quantum oscillations and magnetic robustness relevant for spintronic applications.

Contribution

It provides the first comprehensive analysis of RAlSi Weyl semimetals, highlighting their quantum oscillations, magnetic behavior, and potential for spintronic device applications.

Findings

Non-saturated magnetoresistance (~900% for SmAlSi, 80% for CeAlSi) at 1.8 K, 9 T.

Carrier densities change significantly around magnetic transition temperatures.

Observation of Shubnikov-de Haas oscillations with nontrivial Berry phase in SmAlSi.

Abstract

Weyl semimetal (WSM) as a new type of quantum state of matter hosting low energy relativistic quasiparticles, has attracted significant attention for both scientific community and potential quantum device applications. Here, we report a comprehensive investigation of the structural, magnetic and transport properties of noncentrosymmetric RAlSi (R = Sm, Ce), which have been predicted to be new magnetic WSM candidates. Both samples exhibit non-saturated magnetoresistance (MR), with ~ 900% for SmAlSi and 80% for CeAlSi at 1.8 K, 9 T. The carrier densities of SmAlSi and CeAlSi display remarkable change around magnetic transition temperatures, signifying that the electronic states are sensitive to magnetic ordering of rare earth elements. At low temperatures, SmAlSi reveals prominent Shubnikov-de Haas (SdH) oscillations associated with the nontrivial Berry phase. High pressure experiments demonstrate that the magnetic order is robust and survival under high pressure. Our results would yield valuable insights of WSM physics and potentials in application to the next-generation spintronic devices in RAX family.