Non-Hermitian topological phase transitions in superlattices and the optical Dirac equation

Abstract

Optical superlattices with sublattice symmetry subjected to a synthetic imaginary gauge field undergo a topological phase transition in the Bloch energy spectrum, characterized by the change of a spectral winding number. For a narrow gap, the phase transition is of universal form and described by a non-Hermitian Dirac equation with Lorentz-symmetry violation. A simple photonic system displaying such a phase transition is discussed, which is based on light coupling in co-propagating gratings.

5 pages, 4 figures

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Cited by in corpus (5)

• Topological photonic crystals: physics, designs and applications
• Non-Hermitian skin effect and self-acceleration
• Non-Hermitian skin effect beyond the tight-binding models
• Investigation of a non-Hermitian edge burst with time-dependent perturbation theory
• Self-healing of non-Hermitian topological skin modes