Competing topological phases in a non-Hermitian time-reversal symmetry-broken Bernevig-Hughes-Zhang model
arXiv:2404.04184 · doi:10.1103/PhysRevB.110.115132
Abstract
The Bernevig-Hughes-Zhang (BHZ) model, which serves as a cornerstone in the study of the quantum spin Hall insulators, showcases robust spin-filtered helical edge states in a nanoribbon geometry. In the presence of an in-plane magnetic field, these (first-order) helical states gap out to be replaced by second-order corner states under suitable open-boundary conditions. Here, we show that the inclusion of a spin-dependent non-Hermitian balanced gain/loss potential induces a competition between these first and second-order topological phases. Surprisingly, the previously dormant first-order helical edge states in the nanoribbon resurface as the non-Hermitian effect intensifies, effectively neutralizing the role played by the magnetic field. By employing the projected spin spectra and the spin Chern number, we conclusively explain the resurgence of the first-order topological properties in the time-reversal symmetry-broken BHZ model in presence of non-Hermiticity. Finally, the biorthogonal spin-resolved Berry phase, exhibiting a non-trivial winding, definitively establishes the topological nature of these revived edge states, emphasizing the dominance of non-Hermiticity over the magnetic field.
arXiv commentPublished in Physical Review B
References in corpus (54)
- Electric Field Effect in Atomically Thin Carbon Films
- Topological Insulators
- Topological insulators and superconductors
- Quantum Spin Hall Effect in Graphene
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Topological Order and the Quantum Spin Hall Effect
- Quantum Spin Hall Insulator State in HgTe Quantum Wells
- Classification of topological quantum matter with symmetries
- Edge states and topological invariants of non-Hermitian systems
- A spin-orbit coupled Bose-Einstein condensate
- Quantized Electric Multipole Insulators
- Dissipationless Quantum Spin Current at Room Temperature
- Exceptional Topology of Non-Hermitian Systems
- Non-Hermitian Physics
- Higher-Order Topological Insulators
- Topological phases of non-Hermitian systems
- The physics of exceptional points
- Electric Multipole Moments, Topological Multipole Moment Pumping, and Chiral Hinge States in Crystalline Insulators
- Chern Numbers in Discretized Brillouin Zone: Efficient Method of Computing (Spin) Hall Conductances
- Symmetry and Topology in Non-Hermitian Physics
- Biorthogonal Bulk-Boundary Correspondence in Non-Hermitian Systems
- Topological Origin of Non-Hermitian Skin Effects
- Topological Band Theory for Non-Hermitian Hamiltonians
- Anomalous edge state in a non-Hermitian lattice
- Non-Bloch Band Theory of Non-Hermitian Systems
- -dimensional edge states of rotation symmetry protected topological states
- Reflection symmetric second-order topological insulators and superconductors
- Spin-orbit coupling in quantum gases
- Spin-Orbit Coupled Degenerate Fermi Gases
- Observation of bulk boundary correspondence breakdown in topolectrical circuits
- Non-Hermitian Boundary Modes
- Anatomy of skin modes and topology in non-Hermitian systems
- Non-Hermitian robust edge states in one-dimension: Anomalous localization and eigenspace condensation at exceptional points
- Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems
- Topolectrical circuits
- Classical higher-order topological insulators
- Hybrid higher-order skin-topological modes in non-reciprocal systems
- Second-Order Topological Phases in Non-Hermitian Systems
- Z2Pack: Numerical Implementation of Hybrid Wannier Centers for Identifying Topological Materials
- Higher-order non-Hermitian skin effect
- Topological properties of linear circuit lattices
- New topological invariants in non-Hermitian systems
- Robustness of the Spin-Chern number
- Spin Hall Insulator
- Time-reversal-symmetry-broken quantum spin Hall effect
- Higher-order topological corner states induced by gain and loss
- Surface State Magnetization and Chiral Edge States on Topological Insulators
- Non-Hermitian extensions of higher-order topological phases and their biorthogonal bulk-boundary correspondence
- Realization of 2D Spin-orbit Interaction and Exotic Topological Orders in Cold Atoms
- Higher Order Topological Phases: A General Principle of Construction
- Engineering Corner States from Two-Dimensional Topological Insulators
- Non-Hermitian higher-order topological superconductors in two-dimension: statics and dynamics
- Circuit realisation of a two-orbital non-Hermitian tight-binding chain
- Non-Hermitian topological phase transitions for quantum spin Hall insulators