Chiral Emission into Nanophotonic Resonators

Abstract

Chiral emission, where the handedness of a transition dipole determines the direction in which a photon is emitted, has recently been observed from atoms and quantum dots coupled to nanophotonic waveguides. Here, we consider the case of chiral light-matter interactions in resonant nanophotonic structures, deriving closed-form expressions for the fundamental quantum electrodynamic quantities that describe these interactions. We show how parameters such as the position dependent, directional Purcell factors and mode volume can be calculated using computationally efficient two dimensional eigenmode simulations. As an example, we calculate these quantities for a prototypical ring resonator with a geometric footprint of only 4.5 µm 2 , showing that perfect directionality with a simultaneous Purcell enhancement upwards of 400 are possible. The ability to determine these fundamental properties of nanophotonic chiral interfaces is crucial if they are to form elements of quantum circuits and networks.

Chiral Photonic Circuits for Deterministic Spin Transfer

“…A promising approach is to exploit chiral quantum optics to form a chiral interface that facilitates the unidirectional transfer of the spin to the guided photons. [27] To date, chiral coupling has been intensively evaluated in various nanophotonic structures including metal surfaces, [28,29] optical fibers, [30,31] semiconductor waveguides, [32][33][34][35] microresonators, [36][37][38][39][40][41][42][43] and topological nanostructures. [44,45] Particularly, the tightly confined light field carries transverse spin angular momentum; thus, a link between the spin and propagation direction of light can be introduced.…”

“…To date, chiral coupling has been intensively evaluated in various nanophotonic structures including metal surfaces, [ 28,29 ] optical fibers, [ 30,31 ] semiconductor waveguides, [ 32–35 ] microresonators, [ 36–43 ] and topological nanostructures. [ 44,45 ] Particularly, the tightly confined light field carries transverse spin angular momentum; thus, a link between the spin and propagation direction of light can be introduced.…”

Asymmetric coupling between two quantum emitters

“…Novel phenomena stemming from asymmetric coupling have been studied theoretically in a range of systems, including spin networks [27], cavity-based photonic devices [28,29], quantum emitters coupled to plasmonic waveguides [30,31], nanophotonic ring resonators [32,33], synthetic phonons [34], and Janus dipoles [35]. Recently, it was shown that chiral coupling at the nanoscale naturally arises in the system of two circularly polarized quantum emitters held above a metal surface, where the surface plasmons mediating the emitteremitter interactions can be controlled in a manifestation of reservoir engineering [36].…”

Recent Progress in Chiral Topological Quantum Interface

“…A number of associated experiments have been implemented. Besides, this chiral lightmatter interaction between photonic nanostructure and quantum emitter has also been realized in other structures, such as nanobeam waveguides [34,45], optical resonators [46,47], and metamaterials [48]. Here, more details about systematic theoretical research and applications for chiral quantum interface in conventional nanostructures have been reviewed in Ref.…”