Emergent cavity-QED dynamics along the edge of a photonic lattice

TL;DR

This paper explores how qubits interact with flat-band edge modes in a photonic lattice, revealing unique cavity-QED dynamics, including tunable localization and potential for quantum information transfer, with a proposed superconducting circuit implementation.

Contribution

It introduces a dissipative cavity QED model for edge modes in a photonic lattice, highlighting unconventional localization and dynamics not seen in traditional systems.

Findings

Effective coupling to a superposition of edge modes

Unconventional power law localization of the mode

Predicted vacuum Rabi oscillations and state transfer

Abstract

We investigate qubits coupled to the boundary of a two dimensional photonic lattice that supports dispersionless edge modes, unlike conventional edge modes that sustain propagating photons. As a case study, we consider a honeycomb lattice (photonic graphene) of coupled resonators with a zigzag edge, where the edge modes form a flat band defined only over a restricted region of momentum space. We show that light matter interactions are effectively captured by a dissipative cavity QED model, wherein the emitter coherently couples to a fictitious cavity mode emerging as a superposition of edge modes. This mode has support on only one sublattice and, most notably, displays an unconventional power law localization around the qubit, yet remaining normalizable in the thermodynamic limit, with a spatial range that can be tuned by introducing lattice anisotropy We predict occurrence of vacuum Rabi oscillations and efficient state transfer between distant emitters. An experimental demonstration using superconducting circuits is proposed.