Two-dimensional non-Hermitian topological phases induced by asymmetric hopping in a one-dimensional superlattice
TLDR
In this paper, two unique classes of non-Hermitian two-dimensional topological phases, a $2\mathbb{Z}$ non-hermitian Chern insulator and a $1.5$ topological semimetal, can be realized by tuning staggered non-HMM or asymmetric hopping strengths in a one-dimensional superlattice.Abstract:
Non-Hermitian systems can host topological states with unusual topological invariants and bulk-edge correspondences that are distinct from conventional Hermitian systems. Here we show that two unique classes of non-Hermitian two-dimensional topological phases, a $2\mathbb{Z}$ non-Hermitian Chern insulator and a ${\mathbb{Z}}_{2}$ topological semimetal, can be realized by solely tuning staggered non-Hermitian or asymmetric hopping strengths in a one-dimensional (1D) superlattice. These non-Hermitian topological phases support real edge modes due to robust $\mathcal{PT}$-symmetric-like spectra and can coexist in a certain parameter regime. The proposed phases can be experimentally realized in photonic or atomic systems and may open an avenue for exploring unique classes of non-Hermitian topological phases with 1D superlattices.read more
Citations
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