8 papers
Algebraic States in Continuum in Dimensional Non-Hermitian Systems
Ao Yang, Kai Zhang, Chen Fang
We report the existence of algebraically localized eigenstates embedded within the continuum spectrum of 2D non-Hermitian systems with a single impurity. These modes, which we term…
Tailoring Bound State Geometry in High-Dimensional Non-Hermitian Systems
Ao Yang, Zixi Fang, Kai Zhang +1
It is generally believed that the non-Hermitian effect (NHSE), due to its non-reciprocal nature, creates barriers for the appearance of impurity bound states. In this paper, we fin…
Resolution of Topology and Geometry from Momentum-Resolved Spectroscopies
Shaofeng Huang, Chen Fang
Extracting the complete quantum geometric and topological character of Bloch wavefunctions from experiments remains a challenge in condensed matter physics. Here, we resolve this b…
A Unified Symmetry Classification of Magnetic Orders via Spin Space Groups: Prediction of Coplanar Even-Wave Phases
Ziyin Song, Ziyue Qi, Chen Fang +2
Spin space groups (SSGs) impose fundamentally different constraints on magnetic configurations in real and reciprocal spaces. As a consequence, the correspondence between real-spac…
Exceptional points and spectral cusps from density-wave fluctuation
Zixi Fang, Chen Fang
We report two types of singularities that arise from fluctuations during the formation of charge- or spin-density waves. The first is the exceptional point (EP), corresponding to a…
Real-time edge dynamics of non-Hermitian lattices
Tian-Hua Yang, Chen Fang
We derive the asymptotic forms of the Green's function at the open edges of general non-Hermitian band systems in all dimensions in the long-time limit, using a modified saddle-poi…