2014/05/22 by Baogang Zhu, Rong Lu, Rong Lü +1 · 7 citations
Mathematics · Physics and Astronomy · #Boundary (topology) #Geometry #Hermitian matrix #Mathematical analysis #Mathematical physics #Mathematics #Nonlinear Photonic Systems #Physics #Quantum Mechanics and Non-Hermitian Physics #Quantum mechanics #Symmetry (geometry) #Topological Materials and Phenomena #cond-mat.other #quant-ph
paper · pdf · doi:10.1103/physreva.89.062102
published as Phys. Rev. A 89, 062102 (2014) · 6 pages, 4 figures, Phys. Rev. A in press
arxiv created 2014/05/22 · openalex publication_date 2014/06/03 · arxiv updated 2014/06/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study the parity- and time-reversal (PT) symmetric non-Hermitian Su-Schrieffer-Heeger (SSH) model with two conjugated imaginary potentials \ifmmode±\else\textpm\fii\ensuremathγ at two end sites. The SSH model is known as one of the simplest two-band topological models which has topologically trivial and nontrivial phases. We find that the non-Hermitian terms can lead to different effects on the properties of the eigenvalues spectrum in topologically trivial and nontrivial phases. In the topologically trivial phase, the system undergos an abrupt transition from the unbroken PT-symmetry region to the spontaneously broken PT-symmetry region at a certain \ensuremathγc, and a second transition occurs at another transition point \ensuremathγ_c^^\ensuremath' when further increasing the strength of the imaginary potential \ensuremathγ. But in the topologically nontrivial phase, the zero-mode edge states become unstable for arbitrary nonzero \ensuremathγ and the PT symmetry of the system is spontaneously broken, which is characterized by the emergence of a pair of conjugated imaginary modes.