8 papers
Topological Correspondence between Hermitian and Non-Hermitian Systems: Anomalous Dynamics
Jong Yeon Lee, Junyeong Ahn, Hengyun Zhou +1
The hallmark of symmetry-protected topological (SPT) phases is the existence of anomalous boundary states, which can only be realized with the corresponding bulk system. In this wo…
Higher-Order Topological Superconductivity of Spin-Polarized Fermions
Junyeong Ahn, Bohm-Jung Yang
We study the superconductivity of spin-polarized electrons in centrosymmetric ferromagnetic metals. Due to the spin-polarization and the Fermi statistics of electrons, the supercon…
Fragile Topology Protected by Inversion Symmetry: Diagnosis, Bulk-Boundary Correspondence, and Wilson Loop
Yoonseok Hwang, Junyeong Ahn, Bohm-Jung Yang
We study the bulk and boundary properties of fragile topological insulators (TIs) protected by inversion symmetry, mostly focusing on the class A of the Altland-Zirnbauer classific…
Two-dimensional higher-order topology in monolayer graphdiyne
Eunwoo Lee, Rokyeon Kim, Junyeong Ahn +1
Based on first-principles calculations and tight-binding model analysis, we propose monolayer graphdiyne as a candidate material for a two-dimensional higher-order topological insu…
Stiefel-Whitney classes and topological phases in band theory
Junyeong Ahn, Sungjoon Park, Dongwook Kim +2
In this article, we review the recent progress in the study of topological phases in systems with space-time inversion symmetry . is an anti-unitary…
Symmetry representation approach to topological invariants in -symmetric systems
Junyeong Ahn, Bohm-Jung Yang
We study the homotopy classification of symmetry representations to describe the bulk topological invariants protected by the combined operation of a two-fold rotation and…