6 citations · 24 across the 12 of their papers we have counts for
5 papers · 1 filter
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…
Engineering high Chern number insulators
Sungjong Woo, Seungbum Woo, Jung-Wan Ryu +1
The concept of Chern insulators is one of the most important buliding block of topological physics, enabling the quantum Hall effect without external magnetic fields. The construct…
Pseudo-Hermitian Topology of Multiband Non-Hermitian Systems
Jung-Wan Ryu, Jae-Ho Han, Chang-Hwan Yi +2
The complex eigenenergies and non-orthogonal eigenstates of non-Hermitian systems exhibit unique topological phenomena that cannot appear in Hermitian systems. Representative examp…
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…