Transfer of arbitrary quantum emitter states to near-field photon superpositions in nanocavities

TL;DR

This paper develops a method to evaluate and analyze the ability of specific photonic crystal cavities, like H1, to transfer quantum superposition states from embedded quantum emitters to confined photonic modes, aiding quantum information transfer.

Contribution

It introduces a dyadic Green's function analysis combined with FDTD simulations to assess superposition support in nanocavities, highlighting the suitability of H1 cavities for quantum state transfer.

Findings

H1 cavities support superposition states on a Poincaré-like sphere.

L3 cavities do not support superposition states.

The method enables comprehensive analysis of superposition transfer capabilities.

Abstract

We present a method to analyze the suitability of particular photonic cavity designs for information exchange between arbitrary superposition states of a quantum emitter and the near-field photonic cavity mode. As an illustrative example, we consider whether quantum dot emitters embedded in "L3" and "H1" photonic crystal cavities are able to transfer a spin superposition state to a confined photonic superposition state for use in quantum information transfer. Using an established dyadic Green's function (DGF) analysis, we describe methods to calculate coupling to arbitrary quantum emitter positions and orientations using the modified local density of states (LDOS) calculated using numerical finite-difference time-domain (FDTD) simulations. We find that while superposition states are not supported in L3 cavities, the double degeneracy of the H1 cavities supports superposition states of the two orthogonal modes that may be described as states on a Poincar\'{e}-like sphere. Methods are developed to comprehensively analyze the confined superposition state generated from an arbitrary emitter position and emitter dipole orientation.