Work

Spin-photon entanglement with direct photon emission in the telecom C-band

Year: 2024

Type: article

Abstract: Quantum networks, relying on the distribution of quantum entanglement between remote locations, have the potential to transform quantum computation and secure long-distance quantum communication. However, a fundamental ingredient for fibre-based implementations of such networks, namely entanglement between a single spin and a photon directly emitted at telecom wavelengths, has been unattainable so far. Here, we use a negatively charged exciton in an InAs/InP quantum dot to implement an optically active spin qubit taking advantage of the lowest-loss transmission window, the telecom C-band. We investigate the coherent interactions of the spin-qubit system under resonant excitation, demonstrating high fidelity spin initialisation and coherent control using picosecond pulses. We further use these tools to measure the coherence of a single, undisturbed electron spin in our system. Finally, we demonstrate spin-photon entanglement in a solid-state system with entanglement fidelity F = 80.07 ± 2.9%, more than 10 standard deviations above the classical limit.

Source: Nature Communications

DOI: 10.1038/s41467-024-53964-1

Authors: P. Laccotripes, T. Müller, R. M. Stevenson, J. Skiba-Szymanska, D. A. Ritchie, A. J. Shields

Institution: University of Cambridge

Language: English

Topic: Quantum and electron transport phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $6,790

Funders: Research Councils UK, University of Sheffield, Ministry of Internal Affairs and Communications, Engineering and Physical Sciences Research Council