edoc

Storing, single photons in broadband vapor cell quantum memories

Buser, Gianni Carlo. Storing, single photons in broadband vapor cell quantum memories. 2023, Doctoral Thesis, University of Basel, Faculty of Science.

[img]
Preview
PDF
Available under License CC0 (Public Domain Dedication).

19Mb

Official URL: https://edoc.unibas.ch/94369/

Downloads: Statistics Overview

Abstract

Single photons are an essential resource for realizing quantum technologies. Together with compatible quantum memories granting control over when a photon arrives, they form a foundational component both of quantum communication and quantum information processing. Quality solid-state single photon sources deliver on the high bandwidths and rates required for scalable quantum technology, but require memories that match these operational parameters. In this thesis, I report on quantum memories based on electromagnetically induced transparency and built in warm rubidium vapor, with such fast and high bandwidth interfaces in mind. I also present work on a heralded single photon source based on parametric downconversion in an optical cavity, operated in a bandwidth regime of a few 100s of megahertz. The systems are characterized on their own and together in a functional interface. As the photon generation process is spontaneous, the memory is implemented as a fully reactive device, capable of storing and retrieving photons in response to an asynchronous external trigger.
The combined system is used to demonstrate the storage and retrieval of single photons in and from the quantum memory. Using polarization selection rules in the Zeeman substructure of the atoms, the read-out noise of the memory is considerably reduced from what is common in ground-state storage schemes in warm vapor. Critically, the quantum signature in the photon number statistics of the retrieved photons is successfully maintained, proving that the emission from the memory is dominated by single photons. We observe a retrieved single-photon state accuracy of $g_{c,\,\text{ret}}^{(2)}=0.177(23)$ for short storage times, which remains $g_{c,\,\text{ret}}^{(2)}<0.5$ throughout the memory lifetime of $680(50)\,$ns. The end-to-end efficiency of the memory interfaced with the photon source is $\eta_{e2e}=1.1(2)\,\%$, which will be further improved in the future by optimizing the operating regime. With its operation bandwidth of $370\,$MHz, our system opens up new possibilities for single-photon synchronization and local quantum networking experiments at high repetition rates.
Advisors:Treutlein, Philipp
Committee Members:Warburton, Richard J and Firstenberg, Ofer
Faculties and Departments:05 Faculty of Science > Departement Physik > Physik > Experimentelle Nanophysik (Treutlein)
UniBasel Contributors:Buser, Gianni and Treutlein, Philipp
Item Type:Thesis
Thesis Subtype:Doctoral Thesis
Thesis no:15010
Thesis status:Complete
Number of Pages:vii, 202
Language:English
Identification Number:
  • urn: urn:nbn:ch:bel-bau-diss150104
edoc DOI:
Last Modified:09 May 2023 04:30
Deposited On:08 May 2023 14:17

Repository Staff Only: item control page