6 papers · 1 filter
Spontaneous emission decay and excitation in photonic time crystals
Jagang Park, Kyungmin Lee, Ruo-Yang Zhang +10
Over the last few decades, the predominant strategies for controlling spontaneous emission have involved tailoring the spatial surroundings of quantum emitters or atoms to create r…
A unified framework for exceptional point pairs in non-Hermitian two-level systems
Jung-Wan Ryu, Jae-Ho Han, Chang-Hwan Yi
Exceptional points (EPs) in non-Hermitian systems are branch singularities where eigenvalues and eigenvectors simultaneously coalesce, leading to rich topological phenomena beyond…
Non-orientable Exceptional Points in Twisted Boundary Systems
Jung-Wan Ryu, Jae-Ho Han, Moon Jip Park +2
Non-orientable manifolds, such as the Möbius strip and the Klein bottle, defy conventional geometric intuition through their twisted boundary conditions. As a result, topological…
Decay Rates of Optical Modes Unveil the Island Structures in Mixed Phase Space
Chang-Hwan Yi, Barbara Dietz, Jae-Ho Han +1
We explore the decay rates of optical modes in asymmetric microcavities with mixed phase space across a wide range of wavelengths that extend deep into the semiclassical, i.e., sho…
Complex energy structures of exceptional point pairs in two level systems
Jung-Wan Ryu, Chang-Hwan Yi, Jae-Ho Han
We investigate the topological properties of multiple exceptional points in non-Hermitian two-level systems, emphasizing vorticity as a topological invariant arising from complex e…
Realization of geometric phase topology induced by multiple exceptional points
Jung-Wan Ryu, Jae-Ho Han, Chang-Hwan Yi
Non-Hermitian systems have Riemann surface structures of complex eigenvalues that admit singularities known as exceptional points. Combining with geometric phases of eigenstates gi…