Unconventional band splitting of CeSb in the devil's staircase transition

TL;DR

This study uses ARPES and DFT to reveal unconventional band splitting in CeSb during its complex devil's staircase magnetic transition, highlighting atypical electronic-magnetic interplay.

Contribution

It uncovers a novel, unconventional band splitting behavior in CeSb associated with its devil's staircase transition, challenging traditional magnetic band splitting models.

Findings

Band splitting occurs around the X point in CeSb.

Energy separation changes abruptly with temperature.

Spectral weights vary gradually across the transition.

Abstract

The interplay between magnetism and electronic band structure is a central theme in condensed matter physics. CeSb, with its complex devil's staircase antiferromagnetic transition, offers a unique opportunity to explore this interplay. Using angle-resolved photoemission spectroscopy (ARPES), we investigate the electronic structure evolution across the devil's staircase transition. Upon entering the antiferromagnetic phase, we observe an intriguing band splitting of the electron pocket around the X point. The energy separation between the split bands changes abruptly with temperature, consistent with the characteristics of the first-order phase transition. However, their respective spectral weights behave gradually with temperature. Combined with our density functional theory (DFT) calculations, we suggest that this atypical behavior deviates from conventional magnetically induced band splitting and potentially arises from the intricate modulation of paramagnetic and antiferromagnetic layers within the devil's staircase transition. Our results provide insights into the complex relationship between electronic structure and magnetism in correlated electron systems.