1. signatures of topological edge states in spin-spin correlations

Sonu Verma

Indian Institute of Technology Kanpur, India

21 June 2021 Mon 11 am

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

Topological systems are characterized by quantized responses and topologically protected surface states. In this seminar, I will focus on some of the topological systems such as quantum Hall insulators (QHI), and quantum spin-Hall insulators (QSHI) in two dimensions and three dimensional Weyl semimetals. In 2D, QHI and QSHI have a gap in the bulk band structure and are characterized by chiral edge modes where a particular spin mode traverse in a given direction. Three dimensional topological Weyl semimetals host even number of band touching points (also known as Weyl nodes) in the bulk band structure and, for finite-geometry, these systems also host topological surface states which form an open arc (also known as Fermi arc) in the surface Brillouin zone. In this seminar, I will talk about the signatures of these topological edge/surface states in spin-spin correlations between localized impurity spins within Rudermann-Kittel-Kausya-Yoshida (RKKY) theory.

1) S. Verma and A. Kundu, Phys. Rev. B 99, 121409 (R) (2019).
2) S. Verma, D. Giri, H. A. Fertig, and A. Kundu, Phys. Rev. B 101, 085419 (2020).