View source for Alain Aspect

{{Use dmy dates|date=October 2022}}
{{Short description|French physicist (born 1947)}}
{{Infobox scientist
| name              = Alain Aspect
| image             = Alain Aspect (26341660894) (cropped).jpg
| caption           = Aspect in 2016
| birth_date        = {{birth date and age||year=1947|month=6|day=15}}
| birth_place       = [[Agen]], Lot-et-Garonne, France
| death_place       = 
| ethnicity         = 
| fields            = [[Physicist]]
| workplaces        = {{ubl|[[École supérieure d'optique|Institut d'Optique]] ([[Paris-Saclay University]])<ref name="Paris-Saclay bio" />|[[École Polytechnique]] ([[Polytechnic Institute of Paris]])<ref name="Paris-Saclay bio">{{Cite web |date=17 February 2020 |title=Alain Aspect |url=http://www.universite-paris-saclay.fr/en/alain-aspect |access-date=4 October 2022 |website=Université Paris-Saclay |language=en}}</ref>|[[Centre national de la recherche scientifique]]|[[Hong Kong Institute for Advanced Study]] ([[City University of Hong Kong]])}}
| alma_mater        = {{ubl|[[École Normale Supérieure de Cachan]]|[[Université d'Orsay]]}}
| education         = 
| doctoral_advisor  = Serge Lowenthal
| thesis1_title     = Contribution à l'étude de la spectrographie de Fourier par holographie
| thesis1_year      = 1971
| thesis1_url       = 
| thesis2_title     = Trois tests expérimentaux des inégalités de Bell par mesure de corrélation de polarisation de photons
| thesis2_year      = 1983
| thesis2_url       = https://worldcat.org/en/title/490591358
| academic_advisors = 
| doctoral_students = 
| notable_students  = 
| known_for         = [[Aspect's experiment]]
| influences        = 
| influenced        = 
| awards            = {{Plainlist|
* [[Fernand Holweck Medal and Prize|Holweck Medal]] (1991)
* [[Wolf Prize in Physics]] (2010)
* [[Albert Einstein Medal]] (2012)
* [[Fellow of the Royal Society|ForMemRS]] (2015)<ref name=royal />
* [[Nobel Prize in Physics]] (2022)}}
| signature         = <!--(filename only)-->
| footnotes         = 
| website           = {{URL|https://www.universite-paris-saclay.fr/en/alain-aspect|universite-paris-saclay.fr/alain-aspect}}
}}

'''Alain Aspect''' ({{IPA|fr|aspɛ|lang|Fr-Aspect.oga}}; born 15 June 1947<ref name="Nobel bio">{{Cite web |title=The Nobel Prize in Physics 2022 |url=https://www.nobelprize.org/prizes/physics/2022/aspect/facts/ |access-date=4 October 2022 |website=NobelPrize.org |language=en-US}}</ref>) is a French  [[physicist]]  noted for his experimental work on  [[quantum entanglement]].<ref>{{cite journal | last1=Aspect | first1=Alain | last2=Grangier | first2=Philippe | last3=Roger | first3=Gérard | title=Experimental Realization of Einstein-Podolsky-Rosen-BohmGedankenexperiment: A New Violation of Bell's Inequalities | journal=Physical Review Letters | publisher=American Physical Society (APS) | volume=49 | issue=2 | date=12 July 1982 | issn=0031-9007 | doi=10.1103/physrevlett.49.91 | pages=91–94| bibcode=1982PhRvL..49...91A | doi-access=free }}</ref><ref>{{cite journal | last1=Aspect | first1=Alain | last2=Dalibard | first2=Jean | last3=Roger | first3=Gérard | title=Experimental Test of Bell's Inequalities Using Time- Varying Analyzers | journal=Physical Review Letters | publisher=American Physical Society (APS) | volume=49 | issue=25 | date=20 December 1982 | issn=0031-9007 | doi=10.1103/physrevlett.49.1804 | pages=1804–1807| bibcode=1982PhRvL..49.1804A | doi-access=free }}</ref><ref name="Aspect2007">{{cite journal|last1=Aspect|first1=Alain|title=Quantum mechanics: To be or not to be local|journal=Nature|volume=446|issue=7138|year=2007|pages=866–867|issn=0028-0836|doi=10.1038/446866a|pmid=17443174|bibcode = 2007Natur.446..866A |s2cid=4397846|doi-access=free}}</ref><ref>{{Cite web |date=17 March 2012 |title=Alain Aspect's Curriculum Vitae, Updated March 2012 |url=https://www.ae-info.org/attach/User/Aspect_Alain/CV/CV%20Alain%20Aspect%20eng%20long%202012%2003%2017.pdf |access-date=4 October 2022 |website=[[Academia Europaea]]}}</ref>

Aspect was awarded the 2022 [[Nobel Prize in Physics]], jointly with [[John Clauser]] and [[Anton Zeilinger]], "for experiments with [[Quantum entanglement|entangled photons]], establishing the violation of [[Bell inequalities]] and pioneering [[quantum information science]]".{{r|nobelprize}}

==Education==
Aspect is a graduate of the [[École Normale Supérieure de Cachan]] (ENS Cachan, today part of [[Paris-Saclay University]]).<ref name="Paris-Saclay bio"/> He passed the ''[[agrégation]]'' in physics in 1969 and received his PhD degree in 1971 from the [[École supérieure d'optique]] (later known as [[Institut d'Optique Graduate School]]) of [[Université d'Orsay]] (later known as [[Université Paris-Sud]]). He then taught for three years in [[Cameroon]] as a replacement for then compulsory military service.<ref>{{Cite web|url=https://lejournal.cnrs.fr/articles/alain-aspect-prix-nobel-de-physique-2022|title=Alain Aspect, prix Nobel de physique 2022|website=cnrs.fr}}</ref>

In the early 1980s, while working on his [[doctorat d'État]] (habilitation thesis),<ref>{{Cite web |url=http://www.lcf.institutoptique.fr/Laboratoire-Charles-Fabry/Groupes-de-recherche/Optique-atomique/Membres/Membres-permanents/Alain-Aspect |title=CV |access-date=5 March 2011 |archive-url=https://web.archive.org/web/20120320235525/http://www.lcf.institutoptique.fr/Laboratoire-Charles-Fabry/Groupes-de-recherche/Optique-atomique/Membres/Membres-permanents/Alain-Aspect |archive-date=20 March 2012 }}</ref> he performed the [[Bell test experiments]] that showed that [[Albert Einstein]], [[Boris Podolsky]] and [[Nathan Rosen]]'s putative [[reductio ad absurdum]] of [[quantum mechanics]], namely that it implied '[[quantum entanglement|ghostly action at a distance]]', did in fact appear to be realized when two [[Elementary particle|particle]]s were separated by an arbitrarily large distance (see [[EPR paradox]] and [[Aspect's experiment]]). A correlation between the particles' [[wave function]]s remains, as long as they were once part of the same undisturbed wave function before one of the child particles was measured. He defended his [[doctorat d'État]] in 1983 at Université Paris-Sud (today part of Paris-Saclay University).<ref>{{Cite web|url=https://www.radiofrance.fr/franceinter/qui-est-alain-aspect-ce-chercheur-francais-co-laureat-du-prix-nobel-de-physique-6227411|title=Qui est Alain Aspect, ce chercheur français co-lauréat du prix Nobel de physique ?|website=radiofrance.fr|date=4 October 2022 }}</ref>

Aspect received an honorary doctorate from [[Heriot-Watt University]] in 2008.<ref>{{Cite web|url=http://www1.hw.ac.uk/annual-review/2008/people_awards.html |title=Annual Review 2008: Principal's Review |website=www1.hw.ac.uk |access-date=29 March 2016 |archive-url=https://web.archive.org/web/20160412040140/http://www1.hw.ac.uk/annual-review/2008/people_awards.html |archive-date=12 April 2016 }}</ref>

==Research==
{{main|Aspect's experiment}}
Aspect's experiments, following the first experiment of [[Stuart Freedman]] and [[John Clauser]] in 1972, were considered to provide further support to the thesis that [[Bell's theorem|Bell's inequalities]] are violated in its [[CHSH Bell test|CHSH]] version, in particular by closing a form of the [[Bell test loopholes|locality loophole]]. However, his results were not completely conclusive since there were loopholes that allowed for alternative explanations that comply with [[Principle of locality|local realism]].<ref>{{cite journal|author=J.-Å. Larsson|title=Loopholes in Bell inequality tests of local realism|journal=J. Phys. A|year=2014|volume=47|issue=42 |article-number=424003|doi=10.1088/1751-8113/47/42/424003 |arxiv=1407.0363 |bibcode=2014JPhA...47P4003L |s2cid=40332044 }}</ref>

After his work on Bell's inequalities, Aspect turned toward studies of [[laser cooling]] of neutral atoms, and  [[Bose–Einstein condensate]]s at the [[Kastler-Brossel Laboratory]].<ref>{{Cite web|url=https://lejournal.cnrs.fr/articles/alain-aspect-prix-nobel-de-physique-2022|title=Alain Aspect, prix Nobel de physique 2022|website=cnrs.fr}}</ref>
[[File:0012-alain-asp preview ecran.jpg|thumb|right|Aspect at the [[École Polytechnique]] ([[Polytechnic Institute of Paris]]).|alt=Picture of Alain Aspect]]
Aspect was deputy director of the French "[[Grandes écoles|grande école]]" [[École supérieure d'optique]] until 1994. He is a member of the [[French Academy of Sciences]] and [[French Academy of Technologies]], and a professor at the [[École Polytechnique]].<ref name="Paris-Saclay bio"/>
[[File: AlainAspectFotoThaler.JPG|thumb|Alain Aspect at the [[Budapest University of Technology and Economics]], 2013.]]

[[File:Alain Aspect, professeur à l’Université Paris-Saclay et à l’École polytechnique, est co-lauréat du Prix Nobel de Physique 2022. (52406154475).jpg|thumb|Alain Aspect at [[Institut d'optique Graduate School|Institut d'Optique]], October 4, 2022.]]

==Distinctions==
Aspect was elected a [[List of Fellows of the Royal Society elected in 2015|Foreign Member of the Royal Society]] (ForMemRS) in 2015.<ref>{{Cite web | url=https://royalsociety.org/people/alain-aspect-11012/ | title=Alain Aspect &#124; Royal Society}}</ref> His certificate of election reads {{quote|For his fundamental experiments in quantum optics and atomic physics. Alain Aspect was the first to exclude subluminal communication between the measurement stations in experimental demonstrations that quantum mechanics invalidates separable hidden-variable theories and the first to demonstrate experimentally the wave–particle duality of single photons. He co-invented the technique of velocity-selective coherent population trapping, was the first to compare the [[Hanbury Brown and Twiss effect|Hanbury Brown-Twiss]] correlations of fermions and bosons under the same conditions, and the first to demonstrate Anderson localization in an ultra-cold atom system. His experiments illuminate fundamental aspects of the quantum-mechanical behaviour of single photons, photon pairs and atoms.<ref name=royal>{{cite web |url=https://collections.royalsociety.org/DServe.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqDb=Catalog&dsqCmd=show.tcl&dsqSearch=(RefNo==%27EC%2F2015%2F48%27) |title=Certificate of Election: EC/2015/48: Aspect, Alain |publisher=The Royal Society |archive-date=2019-07-08 |archive-url=https://web.archive.org/web/20190708184921/https://collections.royalsociety.org/DServe.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqDb=Catalog&dsqCmd=show.tcl&dsqSearch=%28RefNo%3D%3D%27EC%2F2015%2F48%27%29 |location=London }}</ref>}}

In 2005 he was awarded the gold medal of the [[Centre national de la recherche scientifique]], where he is Research Director. The 2010 [[Wolf Prize]] in physics was awarded to Aspect, [[Anton Zeilinger]] and [[John Clauser]]. In 2013 Aspect was awarded both the [[Niels Bohr International Gold Medal]] and the [[UNESCO Niels Bohr Medal]]. In 2011, he was assigned the [[Medal of the City of Paris]]. In 2013, he was also awarded the [[Balzan Prize]] for Quantum Information Processing and Communication. In 2014, he was named Officer of the [[Legion of Honour]].<ref>{{Cite web|url=https://www.inp.cnrs.fr/fr/cnrsinfo/alain-aspect-nomme-membre-honoraire-doptica|title=Alain Aspect nommé membre honoraire d'Optica|website=cnrs.fr|date=4 March 2022 }}</ref>

Asteroid [[33163 Alainaspect]], discovered by astronomers at [[Centre de recherches en géodynamique et astrométrie|Caussols]] in 1998, was named after him.<ref name="MPC-object" /> The official {{MoMP|33163|naming citation}} was published by the [[Minor Planet Center]] on 8 November 2019 ({{small|[[Minor Planet Circulars|M.P.C.]] 118220}}).<ref name="MPC-Circulars-Archive" />

Aspect was awarded the 2022 [[Nobel Prize in Physics]] alongside [[John Clauser|John F. Clauser]] and [[Anton Zeilinger]] "for experiments with entangled [[Photon|photons]], establishing the violation of [[Bell's theorem|Bell's inequalities]] and pioneering quantum information science".<ref name="nobelprize"/>

On 26 June 2025, he was elected to the [[Académie Française]].

==Honours and awards==
Accolades received by Aspect include the following:<ref>{{Cite web|url=https://www.ae-info.org/ae/Member/Aspect_Alain|title=Alain Aspect |website=ae-info.org}}</ref><ref>{{Cite web|url=https://www.academie-sciences.fr/pdf/membre/Aspect_Alain_CV.pdf|title=Alain Aspect's Curriculum Vitae}}</ref>

===Honours===
* 2025 : Elected to the [[Académie Française]].
* 2022 : Commander of the [[Legion of Honour]].
* 2014 : Officier of the [[Legion of Honour]].
* 2011 : Officier of the [[National Order of Merit (France)|National Order of Merit]].
* 2011 : Commander of the [[Ordre des Palmes académiques|Palmes académiques]].
* 2011 : [[Medal of the City of Paris]]. 
* 2005 : Knight of the [[Legion of Honour]].

===Awards===
[[File:Balzan 47.jpg|thumb|Alain Aspect at the [[Balzan Prize]] ceremony ([[Bern]], November 15, 2013).]]
* 2022: [[Nobel Prize in Physics]] (with [[John Clauser]] and [[Anton Zeilinger]])
* 2022: Honorary Optica Member<ref>{{Cite web |title=Alain Aspect {{!}} Optica |url=https://www.optica.org/History/Biographies/bios/Alain_Aspect |access-date=2024-05-09 |website=www.optica.org}}</ref>
* 2013: [[Balzan Prize]] 
* 2013: [[Niels Bohr International Gold Medal]]
* 2013: [[UNESCO Niels Bohr Medal]]
* 2013: [[Frederic Ives Medal/Jarus W. Quinn Prize]]
* 2012: [[Albert Einstein Medal]]
* 2012: Herbert Walther Award
* 2010: [[Wolf Prize]]
* 2005: [[CNRS Gold Medal]]
* 1999: [[Gay-Lussac–Humboldt Prize]]
* 1999: [[Max Born Award]]
* 1991: [[Fernand Holweck Medal and Prize]]
* 1987: International Commission for Optics Award 
* 1985: Commonwealth Award for Science and Invention
* 1983: ''Prix Servant''

===Acknowledgement===
* Member of the [[Academia Europaea]]
* Member of the [[French Academy of Sciences]]
* Member of the [[French Academy of Technologies]]
* Foreign Member of the [[Royal Society]]
* Foreign Associate of the [[National Academy of Sciences]]
* Associate Member of the [[Royal Academy of Science, Letters and Fine Arts of Belgium]]
* Corresponding member abroad of the [[Austrian Academy of Sciences]]
* Fellow and Honorary Member of [[Optica (society)|Optica]]

===Honorary degrees===
* 2006: [[Université de Montréal]]
* 2008: [[Australian National University]]
* 2008: [[Heriot-Watt University]]
* 2010: [[University of Glasgow]]
* 2011: [[University of Haifa]]
* 2014: [[University of Waterloo]]
* 2018: [[City University of Hong Kong]]
* 2023: [[Université de Sherbrooke]]
* 2024: [[University of Minho]]

==Publications==
[[File:Alain Aspect à l'Urfist de Lyon.jpg|thumb|Alain Aspect signing one of his publications in Lyon.]]
* ''Introduction aux lasers et à l'optique quantique'' (with G. Grynberg & C. Fabre), Paris, ed. Ellipses, 1997
* ''Bose-Einstein Condensates and Atom Lasers'' (collectif book), London, ed. Plenum, 2000
* ''Lévy Statistics and Laser Cooling: How Rare Events Bring Atoms to Rest'' (with F. Bardou, J.-Ph. Bouchaud & C. Cohen-Tannoudji), Cambridge, ed.  Cambridge University Press, 2002
* ''Einstein aujourd'hui'' (with M. Le Bellac, M. Leduc, F. Bouchet & É. Brunet), Paris, ed. CNRS, 2005
* ''Introduction to Quantum Optics: From the Semi-classical Approach to Quantized Light'' (with G. Grynberg & C. Fabre), Cambridge, ed. Cambridge University Press, 2010
* ''Single-Photon Generation and Detection: Physics and Application'' (collectif book), London, ed. Academic Press, 2013
* ''Einstein et les révolutions quantiques'', Paris, ed. CNRS, 2019
* ''Si Einstein avait su'', Paris, ed. Odile Jacob, 2025

==References==
{{reflist|30em|refs=

<ref name="MPC-object">{{cite web
  |title      = (33163) Alainaspect
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=33163
  |access-date = 20 November 2019}}</ref>

<ref name="MPC-Circulars-Archive">{{cite web
  |title      = MPC/MPO/MPS Archive
  |work       = Minor Planet Center
  |url        = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
  |access-date = 20 November 2019}}</ref>

<ref name="nobelprize"> <!-- https://archive.today/20221004095301/ --> {{cite press release |url=https://www.nobelprize.org/prizes/physics/2022/press-release/ |title=The Nobel Prize in Physics 2022  |date=October 4, 2022 |work=[[Nobel Prize]] |publisher=[[The Royal Swedish Academy of Sciences ]] |access-date=6 October 2022}}</ref>


}} <!-- end of reflist -->

==Publications==
* {{cite book | last1=Bardou | first1=François | last2=Bouchaud | first2=Jean-Philippe | last3=Aspect | first3=Alain | last4=Cohen-Tannoudji | first4=Claude | title=Lévy Statistics and Laser Cooling | publisher=Cambridge University Press | date=2002 | isbn=978-0-521-00422-0}}
* {{cite book | last=Bell | first=J. S. | title=Speakable and Unspeakable in Quantum Mechanics | date=2004-06-03 | publisher=Cambridge University Press | isbn=0-521-81862-1}}
* {{cite book | last1=Grynberg | first1=Gilbert | last2=Aspect | first2=Alain | last3=Fabre | first3=Claude | title=Introduction to Quantum Optics | publisher=Cambridge University Press | date=2010-09-02 | isbn=978-0-521-55112-0}}

==External links==
{{Commons}}
{{Wikiquote}}
{{Scholia}}
* [https://web.archive.org/web/20120320235525/http://www.lcf.institutoptique.fr/Laboratoire-Charles-Fabry/Groupes-de-recherche/Optique-atomique/Membres/Membres-permanents/Alain-Aspect Aspect's homepage]
* [http://www2.cnrs.fr/en/394.htm Biography] at CNRS
* [http://www.balzan.org/en/prizewinners/alain-aspect Alain Aspect] International Balzan Prize Foundation
* [https://av.tib.eu/search?f=creator%3Bhttp://d-nb.info/gnd/133391388 Videos of Alain Aspect] in the AV-Portal of the [[German National Library of Science and Technology]]
* {{nobelprize|1012}}

{{Wolf Prize in Physics}}
{{FRS 2015}}
{{Nobel Prize in Physics}}
{{2022 Nobel Prize winners}}
{{Académie française Seat 22}}
{{AcademieFrancaiseCurrentMembers}}
{{incubator|vai/ꕉꗷꘋ ꕉꔻꗨ}}
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{{DEFAULTSORT:Aspect, Alain}}
[[Category:1947 births]]
[[Category:Living people]]
[[Category:People from Agen]]
[[Category:20th-century French physicists]]
[[Category:Members of the French Academy of Sciences]]
[[Category:Wolf Prize in Physics laureates]]
[[Category:Foreign associates of the National Academy of Sciences]]
[[Category:Niels Bohr International Gold Medal recipients]]
[[Category:UNESCO Niels Bohr Medal recipients]]
[[Category:Albert Einstein Medal recipients]]
[[Category:Foreign members of the Royal Society]]
[[Category:Members of the Royal Academy of Belgium]]
[[Category:Members of Academia Europaea]]
[[Category:Fellows of the American Physical Society]]
[[Category:Members of the Austrian Academy of Sciences]]
[[Category:École Normale Supérieure alumni]]
[[Category:Academic staff of École Polytechnique]]
[[Category:Nobel laureates in Physics]]
[[Category:French Nobel laureates]]
[[Category:Research directors of the French National Centre for Scientific Research]]
[[Category:Members of the Académie Française]]