# Multi-dimensional photonic states from a quantum dot

## TL;DR

This paper demonstrates a method to generate high-dimensional quantum states, specifically W-states, across multiple time bins using a charged quantum dot, scalable without loss of coherence, advancing quantum information processing.

## Contribution

It introduces a scalable technique to produce high-dimensional time-bin superposed quantum states from a quantum dot using repeated Raman scattering.

## Key findings

- Successfully created W-states superposed across multiple time bins.
- Method maintains coherence and single-photon purity at larger dimensions.
- Framework for deterministic creation of arbitrary time-bin encoded qudits.

## Abstract

Quantum states superposed across multiple particles or degrees of freedom are of crucial importance for the development of quantum technologies. Creating these states deterministically and with high effciency is an ongoing challenge. A promising approach is the repeated excitation of multi-level quantum emitters, which have been shown to naturally generate light with quantum statistics. Here we describe how to create one class of higher dimensional quantum state, a so called W-state, which is superposed across multiple time bins. We do this by repeated Raman scattering of photons from a charged quantum dot in a pillar microcavity. We show this method can be scaled to larger dimensions with no reduction in coherence or single photon character. We explain how to extend this work to enable the deterministic creation of arbitrary time-bin encoded qudits.