36 citations · 87 across the 5 of their papers we have counts for
5 papers
Invisible flat bands on a topological chiral edge
Youjiang Xu, Irakli Titvinidze, Walter Hofstetter
We prove that invisible bands associated with zeros of the single-particle Green's function exist ubiquitously at topological interfaces of 2D Chern insulators, dual to the chiral…
Multicriticality and quantum fluctuation in generalized Dicke model
Youjiang Xu, Diego Fallas Padilla, Han Pu
We consider an important generalization of the Dicke model in which multi-level atoms, instead of two-level atoms as in conventional Dicke model, interact with a single photonic mo…
Building Flat-Band Lattice Models from Gram Matrices
Youjiang Xu, Han Pu
We propose a powerful and convenient method to systematically design flat-band lattice models, which overcomes the difficulties underlying the previous method. Especially, our meth…
Emergent Universality in a Quantum Tricritical Dicke Model
Youjiang Xu, Han Pu
We propose a generalized Dicke model which supports a quantum tricritical point. We map out the phase diagram and investigate the critical behaviors of the model through exact low-…
Number-conserving interacting fermion models with exact topological superconducting ground states
Zhiyuan Wang, Youjiang Xu, Han Pu +1
We present a method to construct number-conserving Hamiltonians whose ground states exactly reproduce an arbitrarily chosen BCS-type mean-field state. Such parent Hamiltonians can…