Chiral photonic circuits for deterministic spin transfer

TL;DR

This paper demonstrates compact chiral photonic circuits with deterministic spin-dependent routing and beamsplitting, advancing quantum information processing by enabling efficient spin-to-path conversion using quantum dots and waveguides.

Contribution

It introduces a novel design of chiral photonic circuits with deterministic circular polarization routing and beamsplitting, utilizing lateral waveguides coupled with quantum dots.

Findings

Achieved a chiral contrast of up to 0.84 in the circuits.

Demonstrated spin- and position-dependent directional emission.

Enabled scalable quantum photonic network components.

Abstract

Chiral quantum optics has attracted considerable interest in the field of quantum information science. Exploiting the spin-polarization properties of quantum emitters and engineering rational photonic nanostructures has made it possible to transform information from spin to path encoding. Here, compact chiral photonic circuits with deterministic circularly polarized chiral routing and beamsplitting are demonstrated using two laterally adjacent waveguides coupled with quantum dots. Chiral routing arises from the electromagnetic field chirality in waveguide, and beamsplitting is obtained via the evanescent field coupling. The spin- and position-dependent directional spontaneous emission are achieved by spatially selective micro-photoluminescence measurements, with a chiral contrast of up to 0.84 in the chiral photonic circuits. This makes a significant advancement for broadening the application scenarios of chiral quantum optics and developing scalable quantum photonic networks.