Band-spin-valley coupled exciton physics in antiferromagnetic MnPS$_3$

Fuente: arXiv
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Main Authors: Wang, Dan, Chen, Haowei, Pang, Yu, Zou, Xiaolong, Duan, Wenhui
Format: Preprint
Published: 2025
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_version_ 1866914051752198144
author Wang, Dan
Chen, Haowei
Pang, Yu
Zou, Xiaolong
Duan, Wenhui
author_facet Wang, Dan
Chen, Haowei
Pang, Yu
Zou, Xiaolong
Duan, Wenhui
contents The introduction of intrinsic magnetic order in two-dimensional (2D) semiconductors offers great opportunities for investigating correlated excitonic phenomena. Here, we employ full-spinor GW plus Bethe-Salpeter equation methodology to reveal rich exciton physics in a prototypical 2D Néel-type antiferromagnetic semiconductor MnPS$_3$, enabled by the interplay among inverted dispersion of the second valence band, spin-valley coupling and magnetic order. The negative hole mass increases the reduced mass of the lowest-energy bright exciton, leading to exchange splitting enhancement of the bright exciton relative to band-edge dark exciton. Notably, such splitting couples with spontaneous valley polarization to generate distinct excitonic fine structure between $K$ and $-K$ valleys, which dictate distinct relaxation behaviors. Crucially, magnetic order transition from Néel antiferromagnetic to ferromagnetic state induces significant quasiparticle band structure reconstruction and excitonic transitions modification, with low-energy optical excitations being exclusively contributed by majority-spin channel. These findings establish 2D antiferromagnetic semiconductors as an intriguing platform to study band-spin-valley coupled exciton physics.
format Preprint
id arxiv_https___arxiv_org_abs_2504_14821
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Band-spin-valley coupled exciton physics in antiferromagnetic MnPS$_3$
Wang, Dan
Chen, Haowei
Pang, Yu
Zou, Xiaolong
Duan, Wenhui
Materials Science
The introduction of intrinsic magnetic order in two-dimensional (2D) semiconductors offers great opportunities for investigating correlated excitonic phenomena. Here, we employ full-spinor GW plus Bethe-Salpeter equation methodology to reveal rich exciton physics in a prototypical 2D Néel-type antiferromagnetic semiconductor MnPS$_3$, enabled by the interplay among inverted dispersion of the second valence band, spin-valley coupling and magnetic order. The negative hole mass increases the reduced mass of the lowest-energy bright exciton, leading to exchange splitting enhancement of the bright exciton relative to band-edge dark exciton. Notably, such splitting couples with spontaneous valley polarization to generate distinct excitonic fine structure between $K$ and $-K$ valleys, which dictate distinct relaxation behaviors. Crucially, magnetic order transition from Néel antiferromagnetic to ferromagnetic state induces significant quasiparticle band structure reconstruction and excitonic transitions modification, with low-energy optical excitations being exclusively contributed by majority-spin channel. These findings establish 2D antiferromagnetic semiconductors as an intriguing platform to study band-spin-valley coupled exciton physics.
title Band-spin-valley coupled exciton physics in antiferromagnetic MnPS$_3$
topic Materials Science
url https://arxiv.org/abs/2504.14821