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.
© 2021 Optical Society of America
Full Article | PDF ArticleMore Like This
Stefano Longhi
Opt. Lett. 48(23) 6251-6254 (2023)
Stefano Longhi
Opt. Lett. 44(5) 1190-1193 (2019)
Stefano Longhi
Opt. Lett. 46(24) 6107-6110 (2021)