Department of Physics, Kyungpook National University
경북대학교 물리학과

KNU Physics Colloquium Series

Optoelectronic manifestation of orbital angular momentum driven by chiral hopping in trigonal Se chains

by Prof. 정우 김 (인천대학교)

Asia/Seoul
B119호 (219동)

B119호

219동

Description

Chiral materials have garnered significant attention in the field of condensed matter physics. Nevertheless, the magnetic moment induced by the chiral spatial motion of electrons in helical materials, such as elemental Te and Se, remains inadequately understood. In this talk, I present the development of quantum angular momentum enforced by chirality using static and time-dependent density functional theory calculations for an elemental Se chain. Our findings reveal the emergence of an unconventional orbital texture driven by the chiral geometry, giving rise to a non-vanishing current-induced orbital moment. By incorporating spin-orbit coupling, we demonstrate that a current-induced spin accumulation arises in the chiral chain, which fundamentally differs from the conventional Edelstein effect. Furthermore, we demonstrate the optoelectronic detection of the orbital angular momentum in the chiral Se chain, providing a conceptually novel alternative to the interband Berry curvature, which is ill-defined in low dimensions. Our results provide a fundamental understanding of the interplay between spin and orbital degrees of freedom in chiral geometries, which paves the way for design of novel orbitronic/spintronic devices utilizing chiral materials.