Quantum electrodynamics in anisotropic and tilted Dirac photonic lattices

TL;DR

This paper explores how anisotropic and tilted Dirac photonic lattices can be engineered to control quantum electrodynamics processes like spontaneous emission and photon-mediated interactions, with potential applications in quantum technologies.

Contribution

It introduces methods to tune quantum electrodynamics phenomena by manipulating anisotropic Dirac cone dispersions in photonic lattices, including tilted and semi-Dirac types.

Findings

Anisotropy alters the spatial shape of emitter interactions.

Tilted Dirac cones modify the coherent and incoherent nature of interactions.

Engineered dispersions can be interfaced with quantum emitters for quantum applications.

Abstract

One of the most striking predictions of quantum electrodynamics is that vacuum fluctuations of the electromagnetic field can lead to spontaneous emission of atoms as well as photon-mediated interactions among them. Since these processes strongly depend on the nature of the photonic bath, a current burgeoning field is the study of their modification in the presence of photons with non-trivial energy dispersions, e.g., the ones confined in photonic crystals. A remarkable example is the case of isotropic Dirac-photons, which has been recently shown to lead to non-exponential spontaneous emission as well as dissipation-less long-range emitter interactions. In this work, we show how to further tune these processes by considering anisotropic Dirac cone dispersions, which include tilted, semi-Dirac, and the recently discovered type II and III Dirac points. In particular, we show how by changing the anisotropy of the lattice one can change both the spatial shape of the interactions as well as its coherent/incoherent nature. Finally, we discuss a possible implementation where these energy dispersions can be engineered and interfaced with quantum emitters based on subwavelength atomic arrays.