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Towards Efficient Quantum Memories in Rare-Earth-Ion-Doped Solids

Amari, Atia LU (2010) In Lund Reports on Atomic Physics LRAP-413.
Abstract
This thesis describes experiments aimed at developing a key component in applications such

as quantum networks and long-distance quantum communication systems: quantum memories. Quantum memories for light using photon-echo and coherent rephrasing techniques have been developed.

The work is carried out on rare-earth-ion-doped inorganic crystals. Several properties are associated with these crystals such as long coherence times and long-lived ground state sublevels that are particularly interesting in connection applications in the area of quantum information science.

It is demonstrated the preparation of optical inhomogeneous absorption profiles such that the light only interacts with a specific transition at a... (More)
This thesis describes experiments aimed at developing a key component in applications such

as quantum networks and long-distance quantum communication systems: quantum memories. Quantum memories for light using photon-echo and coherent rephrasing techniques have been developed.

The work is carried out on rare-earth-ion-doped inorganic crystals. Several properties are associated with these crystals such as long coherence times and long-lived ground state sublevels that are particularly interesting in connection applications in the area of quantum information science.

It is demonstrated the preparation of optical inhomogeneous absorption profiles such that the light only interacts with a specific transition at a selected frequency. Narrow absorbing structures with widths of <100 kHz have been prepared with no absorption in the surrounding spectral interval.

Most of the experiments were carried out using Pr3+:Y2SiO5. However, in our search for suitable a Λ-system in the material under consideration, we also performed spectral hole-burning spectroscopy in Nd:Y2SiVO4. As part of the search for host materials for Pr, Pr:La2(WO4)3 crystal was characterized using a variety of methods, such as, hole burning and photon-echoes. Electromagnetically induced transparency was also observed in this crystal.

The most important criteria for evaluating quantum memory performance and the most important physical requirements are discussed. After investigating the standard photon echo techniques and controlled reversible inhomogeneous broadening (CRIB) for quantum state storage, we considered an efficient multimode quantum memory protocol; the atomic frequency comb (AFC) protocol. Combs with peaks of widths 100-300 kHz and an optical depth of~ 10 were created by optical pumping inside an emptied region of the

inhomogeneous profile of Pr3+:Y2SiO5, allowing us to improve the efficiency of light storage. Light storage combining a photon-echo technique based on an AFC and spin-wave storage have been demonstrated, and an experimental AFC scheme for the storage of weak coherent light pulses in Pr3+:Y2SiO5 is presented.

Finally, we have investigated superradiance and slow light effects. Both these effects occur in the high optical depth regime and can influence the memory performance. Under certain conditions superradiance results in the immediate re-emission of the stored light in a single burst of coherent radiation, and inside spectrally structured materials, slow light effects may result when storage is performed. (Less)
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author
supervisor
opponent
  • Prof. Tittel, Wolfgang, Institute for Quantum Information Science, University of Calgary, Alberta, Canada
organization
publishing date
type
Thesis
publication status
published
subject
keywords
rare-earth-ion-doped crystals, spectral hole-burning spectroscopy, AFC, CRIB, superradiance, slow light, Quantum memories, photon echo, EIT
in
Lund Reports on Atomic Physics
volume
LRAP-413
pages
163 pages
publisher
Division of Atomic Physics, Department of Physics, Faculty of Engineering, LTH, Lund University
defense location
Sal B, Fysiska institutionen, Professorsgatan 1, Lund
defense date
2010-03-31 10:15
ISSN
0281-2762
ISBN
978-91-628-8026-2
language
English
LU publication?
yes
id
af386631-d288-40c3-86d9-91869064636a (old id 1553305)
date added to LUP
2010-03-05 13:10:38
date last changed
2018-05-29 10:05:51
@phdthesis{af386631-d288-40c3-86d9-91869064636a,
  abstract     = {This thesis describes experiments aimed at developing a key component in applications such<br/><br>
 as quantum networks and long-distance quantum communication systems: quantum memories. Quantum memories for light using photon-echo and coherent rephrasing techniques have been developed.<br/><br>
The work is carried out on rare-earth-ion-doped inorganic crystals. Several properties are associated with these crystals such as long coherence times and long-lived ground state sublevels that are particularly interesting in connection applications in the area of quantum information science.<br/><br>
It is demonstrated the preparation of optical inhomogeneous absorption profiles such that the light only interacts with a specific transition at a selected frequency. Narrow absorbing structures with widths of &lt;100 kHz have been prepared with no absorption in the surrounding spectral interval.<br/><br>
Most of the experiments were carried out using Pr3+:Y2SiO5. However, in our search for suitable a Λ-system in the material under consideration, we also performed spectral hole-burning spectroscopy in Nd:Y2SiVO4. As part of the search for host materials for Pr, Pr:La2(WO4)3 crystal was characterized using a variety of methods, such as, hole burning and photon-echoes. Electromagnetically induced transparency was also observed in this crystal.<br/><br>
The most important criteria for evaluating quantum memory performance and the most important physical requirements are discussed. After investigating the standard photon echo techniques and controlled reversible inhomogeneous broadening (CRIB) for quantum state storage, we considered an efficient multimode quantum memory protocol; the atomic frequency comb (AFC) protocol. Combs with peaks of widths 100-300 kHz and an optical depth of~ 10 were created by optical pumping inside an emptied region of the<br/><br>
 inhomogeneous profile of Pr3+:Y2SiO5, allowing us to improve the efficiency of light storage. Light storage combining a photon-echo technique based on an AFC and spin-wave storage have been demonstrated, and an experimental AFC scheme for the storage of weak coherent light pulses in Pr3+:Y2SiO5 is presented.<br/><br>
Finally, we have investigated superradiance and slow light effects. Both these effects occur in the high optical depth regime and can influence the memory performance. Under certain conditions superradiance results in the immediate re-emission of the stored light in a single burst of coherent radiation, and inside spectrally structured materials, slow light effects may result when storage is performed.},
  author       = {Amari, Atia},
  isbn         = {978-91-628-8026-2},
  issn         = {0281-2762},
  keyword      = {rare-earth-ion-doped crystals,spectral hole-burning spectroscopy,AFC,CRIB,superradiance,slow light,Quantum memories,photon echo,EIT},
  language     = {eng},
  pages        = {163},
  publisher    = {Division of Atomic Physics, Department of Physics, Faculty of Engineering, LTH, Lund University},
  school       = {Lund University},
  series       = {Lund Reports on Atomic Physics},
  title        = {Towards Efficient Quantum Memories in Rare-Earth-Ion-Doped Solids},
  volume       = {LRAP-413},
  year         = {2010},
}