4 papers
Hierarchic superradiant phases in anisotropic Dicke model
D. K. He, Z. Song
We revisit the phase diagram of an anisotropic Dicke model by revealing the non-analyticity induced by underlying exceptional points. We find that, from a dynamical perspective, th…
Hilbert Space Fragmentation in Hardcore Bose and Fermi Hubbard Models on Generalized Lieb Lattices
D. K. He, Z. Song
We study the Hilbert space fragmentation (HSF) in hardcore Bose and Fermi Hubbard models in the framework of the restricted spectrum generating algebra (RSGA). We present a family…
-pairing states in the Hubbard model with non-uniform Hubbard interaction
D. K. He, Z. Song
The existence of -pairing eigenstates in the fermionic Hubbard model is fundamentally rooted in the -pairing symmetry, which may hold for systems with non-uniform Hubbard i…
Higher order coherence as witness of exceptional point in Hermitian bosonic Kitaev dimer
D. K. He, Z. Song
The non-analyticity induced by exceptional points (EPs) has manifestations not only in non-Hermitian but also in Hermitian systems. In this work, we focus on a minimal Hermitian bo…