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Quantum Storage of Light Using Nanophotonic Resonators Coupled to Erbium Ion Ensembles


Craiciu, Ioana (2020) Quantum Storage of Light Using Nanophotonic Resonators Coupled to Erbium Ion Ensembles. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/yn6n-7x40.


This thesis presents on-chip quantum storage of telecommunication wavelength light using nanophotonic resonators coupled to erbium ions. Storage of light in an optical quantum memory has applications in quantum information and quantum communication. For example, long distance quantum communication using quantum repeater protocols is enabled by quantum memories. Efficient and broadband quantum memories can be made from resonators coupled to ensembles of atoms. Like other rare earth ions, erbium is appealing for quantum applications due to its long optical and hyperfine coherence times in the solid state at low temperatures. However, erbium is unique among rare earth ions in having an optical transition in the telecommunication C band (1540 nm), making it particularly appealing for quantum communication applications. In this work, we use nano-scale resonators coupled to erbium-167 ions in yttrium orthosilicate crystals (167Er 3+:Y2SiO5).

We demonstrate quantum storage in two types of resonators. In a nanobeam photonic crystal resonator milled directly in 167Er 3+:Y2SiO5, we show storage of weak coherent states using the atomic frequency comb protocol. The storage fidelity for single photon states is estimated to be at least 93.7% ± 2.4% using decoy state analysis, Storage of up to 10 μs and multimode storage are demonstrated. Using a hybrid amorphous silicon 167Er 3+:Y2SiO5 resonator and on-chip electrodes, we demonstrate a multifunctional memory using the atomic frequency comb protocol with DC Stark shift control. In addition dynamic control of memory time, Stark shift control allows modifications to the frequency and bandwidth of stored light. We show tuning of the output pulse by ± 20 MHz relative to the input pulse, and broadening of the pulse bandwidth by more than a factor of three. The storage efficiency in both devices was limited to < 1%.

On the way to these results, we describe 167Er 3+:Y2SiO5 spectroscopy measurements including optical coherence times and hyperfine lifetimes below 1 K, and we estimate the linear DC stark shift along two crystal directions. The design and fabrication of the on-chip resonators is presented. We discuss the limitations to storage time and efficiency, including superhyperfine coupling and resonator parameters, and we outline a path forward for improving the storage efficiency in these types of devices.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:rare earth ions; erbium; quantum memory; nanophotonic resonator; cavity quantum electrodynamics; silicon photonics; quantum light-matter interfaces;
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Applied Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Faraon, Andrei
Group:Institute for Quantum Information and Matter, Kavli Nanoscience Institute
Thesis Committee:
  • Vahala, Kerry J. (chair)
  • Faraon, Andrei
  • Painter, Oskar J.
  • Endres, Manuel A.
Defense Date:19 May 2020
Funding AgencyGrant Number
Air Force Office of Scientific ResearchFA9550-15-1-0252
Air Force Office of Scientific ResearchFA9550-18-1-0374
Air Force Office of Scientific ResearchFA9550-15-1-0029
National Science FoundationEFRI 1741707
Natural Sciences and Engineering Research Council of CanadaPGSD2-502755-2017
Record Number:CaltechTHESIS:06012020-134801698
Persistent URL:
Related URLs:
URLURL TypeDescription adapted for Chapter 5 ItemAlso available in Evan Miyazono's Caltech PhD thesis
Craiciu, Ioana0000-0002-8670-0715
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13759
Deposited By: Ioana Craiciu
Deposited On:02 Jun 2020 16:52
Last Modified:28 Feb 2023 18:28

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