# Quantum memory and gates using a Lambda-type quantum emitter coupled to a chiral waveguide

## TL;DR

This paper proposes a controllable quantum interface using a Lambda-type emitter coupled to a chiral waveguide, enabling quantum gates and high-fidelity photon storage for scalable quantum networks.

## Contribution

It introduces a novel chiral waveguide system that facilitates deterministic quantum gates and photon storage, advancing quantum network components.

## Key findings

- Enables SWAP and hybrid-entangling gates between emitter and photon.
- Achieves high-fidelity, efficient single-photon storage and retrieval.
- Provides a scalable platform for quantum network building blocks.

## Abstract

By coupling a $\Lambda$-type quantum emitter to a chiral waveguide, in which the polarization of a photon is locked to its propagation direction, we propose a controllable photon-emitter interface for quantum networks. We show that this chiral system enables the SWAP gate and a hybrid-entangling gate between the emitter and a flying single photon. It also allows deterministic storage and retrieval of single-photon states with high fidelities and efficiencies. In short, this chirally coupled emitter-photon interface can be a critical building block toward a large-scale quantum network.