Tachyonic Dispersion in Coherent Networks

Abstract

We propose a technique to realize a tachyonic band structure in a coherent network, such as an array of coupled ring resonators. This is achieved by adding "PT symmetric" spatially-balanced gain and loss to each node of the network. In a square-lattice network, the quasi-energy bandstructure exhibits a tachyonic dispersion relation, centered at either the center or corner of the Brillouin zone. There is one tachyonic hyperboloid in each gap, unlike in PT-symmetric tight-binding honeycomb lattices where the hyperboloids occur in pairs. The dispersion relation can be probed by measuring the peaks in transmission across a finite network as the gain/loss parameter is varied.

6 pages, 5 figures

References in corpus (3)

• PT-symmetry breaking and laser-absorber modes in optical scattering systems
• Network Models of Photonic Floquet Topological Insulators
• Nonhermitian transport effects in coupled-resonator optical waveguides

Cited by in corpus (6)

• Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems
• Anomalous Topological Phases and Unpaired Dirac Cones in Photonic Floquet Topological Insulators
• Exceptional Points in a Non-Hermitian Topological Pump
• Conical intersections for light and matter waves
• Topological edge states in photonic Floquet insulator with unpaired Dirac cones
• Synthetic gauge field and pseudospin-orbit interaction in a stacked two-dimensional ring-network lattice