Magnetic-field-induced nontrivial electronic state in the Kondo-lattice semimetal CeSb

TL;DR

This study reveals that applying a magnetic field to the Kondo semimetal CeSb induces a nontrivial topological electronic state, combining experimental measurements and theoretical calculations to uncover its complex electronic structure.

Contribution

It demonstrates the magnetic-field-induced emergence of nontrivial topological states in CeSb through combined experimental and computational analysis.

Findings

Observation of quantum oscillations indicating a nontrivial Berry phase

Identification of an elongated electron pocket similar to LaBi

First-principle calculations showing spin splitting in ferromagnetic state

Abstract

Synergic effect of electronic correlation and spin-orbit coupling is an emerging topic in topological materials. Central to this rapidly developing area are the prototypes of strongly correlated heavy-fermion systems. Recently, some Ce-based compounds are proposed to host intriguing topological nature, among which the electronic properties of CeSb are still under debate. In this paper, we report a comprehensive study combining magnetic and electronic transport measurements, and electronic band structure calculations of this compound to identify its topological nature. Quantum oscillations are clearly observed in both magnetization and magnetoresistance at high fields, from which one pocket with a nontrivial Berry phase is recognized. Angular-dependent magnetoresistance shows that this pocket is elongated in nature and corresponds to the electron pocket as observed in LaBi. Nontrivial electronic structure of CeSb is further confirmed by first-principle calculations, which arises from spin splitting in the fully polarized ferromagnetic state. These features indicate that magnetic-field can induce nontrivial topological electronic states in this prototypical Kondo semimetal.