---
_id: '40394'
abstract:
- lang: eng
  text: <jats:title>Abstract</jats:title><jats:p>Walk-off effects, originating from
    the difference between the group and phase velocities, limit the efficiency of
    nonlinear optical interactions. While transverse walk-off can be eliminated by
    proper medium engineering, longitudinal walk-off is harder to avoid. In particular,
    ultrafast twin-beam generation via pulsed parametric down-conversion and four-wave
    mixing is only possible in short crystals or fibres. Here we show that in high-gain
    parametric down-conversion, one can overcome the destructive role of both effects
    and even turn them into useful tools for shaping the emission. In our experiment,
    one of the twin beams is emitted along the pump Poynting vector or its group velocity
    matches that of the pump. The result is markedly enhanced generation of both twin
    beams, with the simultaneous narrowing of angular and frequency spectrum. The
    effect will enable efficient generation of ultrafast twin photons and beams in
    cavities, waveguides and whispering-gallery mode resonators.</jats:p>
article_number: '7707'
author:
- first_name: Angela M.
  full_name: Pérez, Angela M.
  last_name: Pérez
- first_name: Kirill Yu
  full_name: Spasibko, Kirill Yu
  last_name: Spasibko
- first_name: Polina
  full_name: Sharapova, Polina
  id: '60286'
  last_name: Sharapova
- first_name: Olga V.
  full_name: Tikhonova, Olga V.
  last_name: Tikhonova
- first_name: Gerd
  full_name: Leuchs, Gerd
  last_name: Leuchs
- first_name: Maria V.
  full_name: Chekhova, Maria V.
  last_name: Chekhova
citation:
  ama: Pérez AM, Spasibko KY, Sharapova P, Tikhonova OV, Leuchs G, Chekhova MV. Giant
    narrowband twin-beam generation along the pump-energy propagation direction. <i>Nature
    Communications</i>. 2015;6(1). doi:<a href="https://doi.org/10.1038/ncomms8707">10.1038/ncomms8707</a>
  apa: Pérez, A. M., Spasibko, K. Y., Sharapova, P., Tikhonova, O. V., Leuchs, G.,
    &#38; Chekhova, M. V. (2015). Giant narrowband twin-beam generation along the
    pump-energy propagation direction. <i>Nature Communications</i>, <i>6</i>(1),
    Article 7707. <a href="https://doi.org/10.1038/ncomms8707">https://doi.org/10.1038/ncomms8707</a>
  bibtex: '@article{Pérez_Spasibko_Sharapova_Tikhonova_Leuchs_Chekhova_2015, title={Giant
    narrowband twin-beam generation along the pump-energy propagation direction},
    volume={6}, DOI={<a href="https://doi.org/10.1038/ncomms8707">10.1038/ncomms8707</a>},
    number={17707}, journal={Nature Communications}, publisher={Springer Science and
    Business Media LLC}, author={Pérez, Angela M. and Spasibko, Kirill Yu and Sharapova,
    Polina and Tikhonova, Olga V. and Leuchs, Gerd and Chekhova, Maria V.}, year={2015}
    }'
  chicago: Pérez, Angela M., Kirill Yu Spasibko, Polina Sharapova, Olga V. Tikhonova,
    Gerd Leuchs, and Maria V. Chekhova. “Giant Narrowband Twin-Beam Generation along
    the Pump-Energy Propagation Direction.” <i>Nature Communications</i> 6, no. 1
    (2015). <a href="https://doi.org/10.1038/ncomms8707">https://doi.org/10.1038/ncomms8707</a>.
  ieee: 'A. M. Pérez, K. Y. Spasibko, P. Sharapova, O. V. Tikhonova, G. Leuchs, and
    M. V. Chekhova, “Giant narrowband twin-beam generation along the pump-energy propagation
    direction,” <i>Nature Communications</i>, vol. 6, no. 1, Art. no. 7707, 2015,
    doi: <a href="https://doi.org/10.1038/ncomms8707">10.1038/ncomms8707</a>.'
  mla: Pérez, Angela M., et al. “Giant Narrowband Twin-Beam Generation along the Pump-Energy
    Propagation Direction.” <i>Nature Communications</i>, vol. 6, no. 1, 7707, Springer
    Science and Business Media LLC, 2015, doi:<a href="https://doi.org/10.1038/ncomms8707">10.1038/ncomms8707</a>.
  short: A.M. Pérez, K.Y. Spasibko, P. Sharapova, O.V. Tikhonova, G. Leuchs, M.V.
    Chekhova, Nature Communications 6 (2015).
date_created: 2023-01-26T14:27:03Z
date_updated: 2025-12-16T11:14:51Z
department:
- _id: '15'
- _id: '569'
- _id: '170'
- _id: '35'
- _id: '230'
doi: 10.1038/ncomms8707
intvolume: '         6'
issue: '1'
keyword:
- General Physics and Astronomy
- General Biochemistry
- Genetics and Molecular Biology
- General Chemistry
- Multidisciplinary
language:
- iso: eng
publication: Nature Communications
publication_identifier:
  issn:
  - 2041-1723
publication_status: published
publisher: Springer Science and Business Media LLC
status: public
title: Giant narrowband twin-beam generation along the pump-energy propagation direction
type: journal_article
user_id: '16199'
volume: 6
year: '2015'
...
---
_id: '40163'
article_number: '1818'
author:
- first_name: Michael
  full_name: Förtsch, Michael
  last_name: Förtsch
- first_name: Josef U.
  full_name: Fürst, Josef U.
  last_name: Fürst
- first_name: Christoffer
  full_name: Wittmann, Christoffer
  last_name: Wittmann
- first_name: Dmitry
  full_name: Strekalov, Dmitry
  last_name: Strekalov
- first_name: Andrea
  full_name: Aiello, Andrea
  last_name: Aiello
- first_name: Maria V.
  full_name: Chekhova, Maria V.
  last_name: Chekhova
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
- first_name: Gerd
  full_name: Leuchs, Gerd
  last_name: Leuchs
- first_name: Christoph
  full_name: Marquardt, Christoph
  last_name: Marquardt
citation:
  ama: Förtsch M, Fürst JU, Wittmann C, et al. A versatile source of single photons
    for quantum information processing. <i>Nature Communications</i>. 2013;4(1). doi:<a
    href="https://doi.org/10.1038/ncomms2838">10.1038/ncomms2838</a>
  apa: Förtsch, M., Fürst, J. U., Wittmann, C., Strekalov, D., Aiello, A., Chekhova,
    M. V., Silberhorn, C., Leuchs, G., &#38; Marquardt, C. (2013). A versatile source
    of single photons for quantum information processing. <i>Nature Communications</i>,
    <i>4</i>(1), Article 1818. <a href="https://doi.org/10.1038/ncomms2838">https://doi.org/10.1038/ncomms2838</a>
  bibtex: '@article{Förtsch_Fürst_Wittmann_Strekalov_Aiello_Chekhova_Silberhorn_Leuchs_Marquardt_2013,
    title={A versatile source of single photons for quantum information processing},
    volume={4}, DOI={<a href="https://doi.org/10.1038/ncomms2838">10.1038/ncomms2838</a>},
    number={11818}, journal={Nature Communications}, publisher={Springer Science and
    Business Media LLC}, author={Förtsch, Michael and Fürst, Josef U. and Wittmann,
    Christoffer and Strekalov, Dmitry and Aiello, Andrea and Chekhova, Maria V. and
    Silberhorn, Christine and Leuchs, Gerd and Marquardt, Christoph}, year={2013}
    }'
  chicago: Förtsch, Michael, Josef U. Fürst, Christoffer Wittmann, Dmitry Strekalov,
    Andrea Aiello, Maria V. Chekhova, Christine Silberhorn, Gerd Leuchs, and Christoph
    Marquardt. “A Versatile Source of Single Photons for Quantum Information Processing.”
    <i>Nature Communications</i> 4, no. 1 (2013). <a href="https://doi.org/10.1038/ncomms2838">https://doi.org/10.1038/ncomms2838</a>.
  ieee: 'M. Förtsch <i>et al.</i>, “A versatile source of single photons for quantum
    information processing,” <i>Nature Communications</i>, vol. 4, no. 1, Art. no.
    1818, 2013, doi: <a href="https://doi.org/10.1038/ncomms2838">10.1038/ncomms2838</a>.'
  mla: Förtsch, Michael, et al. “A Versatile Source of Single Photons for Quantum
    Information Processing.” <i>Nature Communications</i>, vol. 4, no. 1, 1818, Springer
    Science and Business Media LLC, 2013, doi:<a href="https://doi.org/10.1038/ncomms2838">10.1038/ncomms2838</a>.
  short: M. Förtsch, J.U. Fürst, C. Wittmann, D. Strekalov, A. Aiello, M.V. Chekhova,
    C. Silberhorn, G. Leuchs, C. Marquardt, Nature Communications 4 (2013).
date_created: 2023-01-26T07:42:36Z
date_updated: 2023-01-30T12:44:31Z
department:
- _id: '288'
- _id: '15'
doi: 10.1038/ncomms2838
intvolume: '         4'
issue: '1'
keyword:
- General Physics and Astronomy
- General Biochemistry
- Genetics and Molecular Biology
- General Chemistry
- Multidisciplinary
language:
- iso: eng
publication: Nature Communications
publication_identifier:
  issn:
  - 2041-1723
publication_status: published
publisher: Springer Science and Business Media LLC
status: public
title: A versatile source of single photons for quantum information processing
type: journal_article
user_id: '26263'
volume: 4
year: '2013'
...
---
_id: '40173'
abstract:
- lang: eng
  text: "<jats:title>Here, There, Everywhere</jats:title>\r\n          <jats:p>\r\n
    \           Random walks are a powerful mathematical method that can be used to
    simulate certain processes in biology, chemistry, or even the stock market. They
    present a statistical method for mapping the possible routes that processes can
    take. Quantum walks are expected to be able to probe multiple paths simultaneously.
    Quantum walks have been demonstrated for one-dimensional, or straight-line, walks.
    Now,\r\n            <jats:bold>\r\n              Schreiber\r\n              <jats:italic>et
    al.</jats:italic>\r\n            </jats:bold>\r\n            (p.\r\n            <jats:related-article
    xmlns:xlink=\"http://www.w3.org/1999/xlink\" ext-link-type=\"doi\" page=\"55\"
    related-article-type=\"in-this-issue\" vol=\"336\" xlink:href=\"10.1126/science.1218448\">55</jats:related-article>\r\n
    \           , published online 8 March) demonstrate an optical system that can
    simulate quantum walks over a two-dimensional system, thereby providing the capability
    of describing much more complex processes.\r\n          </jats:p>"
author:
- first_name: Andreas
  full_name: Schreiber, Andreas
  last_name: Schreiber
- first_name: Aurél
  full_name: Gábris, Aurél
  last_name: Gábris
- first_name: Peter P.
  full_name: Rohde, Peter P.
  last_name: Rohde
- first_name: Kaisa
  full_name: Laiho, Kaisa
  last_name: Laiho
- first_name: Martin
  full_name: Štefaňák, Martin
  last_name: Štefaňák
- first_name: Václav
  full_name: Potoček, Václav
  last_name: Potoček
- first_name: Craig
  full_name: Hamilton, Craig
  last_name: Hamilton
- first_name: Igor
  full_name: Jex, Igor
  last_name: Jex
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
citation:
  ama: Schreiber A, Gábris A, Rohde PP, et al. A 2D Quantum Walk Simulation of Two-Particle
    Dynamics. <i>Science</i>. 2012;336(6077):55-58. doi:<a href="https://doi.org/10.1126/science.1218448">10.1126/science.1218448</a>
  apa: Schreiber, A., Gábris, A., Rohde, P. P., Laiho, K., Štefaňák, M., Potoček,
    V., Hamilton, C., Jex, I., &#38; Silberhorn, C. (2012). A 2D Quantum Walk Simulation
    of Two-Particle Dynamics. <i>Science</i>, <i>336</i>(6077), 55–58. <a href="https://doi.org/10.1126/science.1218448">https://doi.org/10.1126/science.1218448</a>
  bibtex: '@article{Schreiber_Gábris_Rohde_Laiho_Štefaňák_Potoček_Hamilton_Jex_Silberhorn_2012,
    title={A 2D Quantum Walk Simulation of Two-Particle Dynamics}, volume={336}, DOI={<a
    href="https://doi.org/10.1126/science.1218448">10.1126/science.1218448</a>}, number={6077},
    journal={Science}, publisher={American Association for the Advancement of Science
    (AAAS)}, author={Schreiber, Andreas and Gábris, Aurél and Rohde, Peter P. and
    Laiho, Kaisa and Štefaňák, Martin and Potoček, Václav and Hamilton, Craig and
    Jex, Igor and Silberhorn, Christine}, year={2012}, pages={55–58} }'
  chicago: 'Schreiber, Andreas, Aurél Gábris, Peter P. Rohde, Kaisa Laiho, Martin
    Štefaňák, Václav Potoček, Craig Hamilton, Igor Jex, and Christine Silberhorn.
    “A 2D Quantum Walk Simulation of Two-Particle Dynamics.” <i>Science</i> 336, no.
    6077 (2012): 55–58. <a href="https://doi.org/10.1126/science.1218448">https://doi.org/10.1126/science.1218448</a>.'
  ieee: 'A. Schreiber <i>et al.</i>, “A 2D Quantum Walk Simulation of Two-Particle
    Dynamics,” <i>Science</i>, vol. 336, no. 6077, pp. 55–58, 2012, doi: <a href="https://doi.org/10.1126/science.1218448">10.1126/science.1218448</a>.'
  mla: Schreiber, Andreas, et al. “A 2D Quantum Walk Simulation of Two-Particle Dynamics.”
    <i>Science</i>, vol. 336, no. 6077, American Association for the Advancement of
    Science (AAAS), 2012, pp. 55–58, doi:<a href="https://doi.org/10.1126/science.1218448">10.1126/science.1218448</a>.
  short: A. Schreiber, A. Gábris, P.P. Rohde, K. Laiho, M. Štefaňák, V. Potoček, C.
    Hamilton, I. Jex, C. Silberhorn, Science 336 (2012) 55–58.
date_created: 2023-01-26T07:59:09Z
date_updated: 2023-01-30T12:46:44Z
department:
- _id: '288'
- _id: '15'
doi: 10.1126/science.1218448
intvolume: '       336'
issue: '6077'
keyword:
- Multidisciplinary
language:
- iso: eng
page: 55-58
publication: Science
publication_identifier:
  issn:
  - 0036-8075
  - 1095-9203
publication_status: published
publisher: American Association for the Advancement of Science (AAAS)
status: public
title: A 2D Quantum Walk Simulation of Two-Particle Dynamics
type: journal_article
user_id: '26263'
volume: 336
year: '2012'
...
---
_id: '48999'
abstract:
- lang: eng
  text: <jats:p>The fast dephasing of electron spins in an ensemble of quantum dots
    is detrimental for applications in quantum information processing. We show here
    that dephasing can be overcome by using a periodic train of light pulses to synchronize
    the phases of the precessing spins, and we demonstrate this effect in an ensemble
    of singly charged (In,Ga)As/GaAs quantum dots. This mode locking leads to constructive
    interference of contributions to Faraday rotation and presents potential applications
    based on robust quantum coherence within an ensemble of dots.</jats:p>
author:
- first_name: A.
  full_name: Greilich, A.
  last_name: Greilich
- first_name: D. R.
  full_name: Yakovlev, D. R.
  last_name: Yakovlev
- first_name: A.
  full_name: Shabaev, A.
  last_name: Shabaev
- first_name: Al. L.
  full_name: Efros, Al. L.
  last_name: Efros
- first_name: I. A.
  full_name: Yugova, I. A.
  last_name: Yugova
- first_name: R.
  full_name: Oulton, R.
  last_name: Oulton
- first_name: V.
  full_name: Stavarache, V.
  last_name: Stavarache
- first_name: Dirk
  full_name: Reuter, Dirk
  id: '37763'
  last_name: Reuter
- first_name: A.
  full_name: Wieck, A.
  last_name: Wieck
- first_name: M.
  full_name: Bayer, M.
  last_name: Bayer
citation:
  ama: Greilich A, Yakovlev DR, Shabaev A, et al. Mode Locking of Electron Spin Coherences
    in Singly Charged Quantum Dots. <i>Science</i>. 2006;313(5785):341-345. doi:<a
    href="https://doi.org/10.1126/science.1128215">10.1126/science.1128215</a>
  apa: Greilich, A., Yakovlev, D. R., Shabaev, A., Efros, Al. L., Yugova, I. A., Oulton,
    R., Stavarache, V., Reuter, D., Wieck, A., &#38; Bayer, M. (2006). Mode Locking
    of Electron Spin Coherences in Singly Charged Quantum Dots. <i>Science</i>, <i>313</i>(5785),
    341–345. <a href="https://doi.org/10.1126/science.1128215">https://doi.org/10.1126/science.1128215</a>
  bibtex: '@article{Greilich_Yakovlev_Shabaev_Efros_Yugova_Oulton_Stavarache_Reuter_Wieck_Bayer_2006,
    title={Mode Locking of Electron Spin Coherences in Singly Charged Quantum Dots},
    volume={313}, DOI={<a href="https://doi.org/10.1126/science.1128215">10.1126/science.1128215</a>},
    number={5785}, journal={Science}, publisher={American Association for the Advancement
    of Science (AAAS)}, author={Greilich, A. and Yakovlev, D. R. and Shabaev, A. and
    Efros, Al. L. and Yugova, I. A. and Oulton, R. and Stavarache, V. and Reuter,
    Dirk and Wieck, A. and Bayer, M.}, year={2006}, pages={341–345} }'
  chicago: 'Greilich, A., D. R. Yakovlev, A. Shabaev, Al. L. Efros, I. A. Yugova,
    R. Oulton, V. Stavarache, Dirk Reuter, A. Wieck, and M. Bayer. “Mode Locking of
    Electron Spin Coherences in Singly Charged Quantum Dots.” <i>Science</i> 313,
    no. 5785 (2006): 341–45. <a href="https://doi.org/10.1126/science.1128215">https://doi.org/10.1126/science.1128215</a>.'
  ieee: 'A. Greilich <i>et al.</i>, “Mode Locking of Electron Spin Coherences in Singly
    Charged Quantum Dots,” <i>Science</i>, vol. 313, no. 5785, pp. 341–345, 2006,
    doi: <a href="https://doi.org/10.1126/science.1128215">10.1126/science.1128215</a>.'
  mla: Greilich, A., et al. “Mode Locking of Electron Spin Coherences in Singly Charged
    Quantum Dots.” <i>Science</i>, vol. 313, no. 5785, American Association for the
    Advancement of Science (AAAS), 2006, pp. 341–45, doi:<a href="https://doi.org/10.1126/science.1128215">10.1126/science.1128215</a>.
  short: A. Greilich, D.R. Yakovlev, A. Shabaev, Al.L. Efros, I.A. Yugova, R. Oulton,
    V. Stavarache, D. Reuter, A. Wieck, M. Bayer, Science 313 (2006) 341–345.
date_created: 2023-11-17T09:15:30Z
date_updated: 2023-11-17T09:16:01Z
department:
- _id: '15'
- _id: '230'
doi: 10.1126/science.1128215
intvolume: '       313'
issue: '5785'
keyword:
- Multidisciplinary
language:
- iso: eng
page: 341-345
publication: Science
publication_identifier:
  issn:
  - 0036-8075
  - 1095-9203
publication_status: published
publisher: American Association for the Advancement of Science (AAAS)
status: public
title: Mode Locking of Electron Spin Coherences in Singly Charged Quantum Dots
type: journal_article
user_id: '42514'
volume: 313
year: '2006'
...