고체전자구조계산연구실에서 서울대학교 물리학과 안준영 박사과정생을 초청하여 아래와 같이 세미나를 개최합니다.

학과 구성원 여러분의 많은 참석을 부탁드립니다.

○ 일시: 2018년 8월 1일(수) 오후 4:00

○ 장소: 물리학과 세미나실 (31355호)

○ 연사: Junyeong Ahn  (Center for Theoretical Physics, Seoul National University)

○ Title: Band Topology in Nodal Line Semimetals with Z2 Monopole Charges

○ Abstract:  Since the discovery of topological insulators and semimetals, there have been many efforts to classify and characterize topological phases of matters. In recent years, three concepts have emerged to become new trends in this direction: fragile topology, higher-order topology, and gap-closing objects (nodes) with multiple topological charges. In this seminar, I will talk about those new concepts based on my recent work on nodal line semimetals hosting nodal lines with two topological charges: one is the well-known pi Berry phase, and the other is the Z2 monopole charge. New analytic methods that I developed for calculating Z2 monopole charges allow systematic studies on this exotic topological charge, which have been difficult up to now. In addition to the theoretical analysis, I will also present a possible material realization based on my colleagues’ first-principles calculations.