Optical Charge Injection and Full Coherent Control of Spin-Qubit in the Telecom C-band Emitting Quantum Dot

TL;DR

This paper demonstrates a new solid-state spin-qubit in InAs/GaAs quantum dots emitting in the telecom C-band, enabling coherent control suitable for quantum communication over fiber networks.

Contribution

It introduces a novel hole spin-qubit platform in quantum dots emitting in the telecom C-band, with demonstrated optical initialization, read-out, and control.

Findings

Hole spin-degeneracy lifted with magnetic field

Successful optical initialization and read-out

Complete coherent control achieved

Abstract

Solid-state quantum emitters with manipulable spin-qubits are promising platforms for quantum communication applications. Although such light-matter interfaces could be realized in many systems only a few allow for light emission in the telecom bands necessary for long-distance quantum networks. Here, we propose and implement a new optically active solid-state spin-qubit based on a hole confined in a single InAs/GaAs quantum dot grown on an InGaAs metamorphic buffer layer emitting photons in the C-band. We lift the hole spin-degeneracy using an external magnetic field and demonstrate hole injection, initialization, read-out and complete coherent control using picosecond optical pulses. These results showcase a new solid-state spin-qubit platform compatible with preexisting optical fibre networks.