Laser cooling of antihydrogen atoms

Baker, Christopher; Bertsche, W.; Capra, A.; Carruth, C.; Cesar, C. L.; Charlton, M.; Christensen, A.; Collister, R.; Cridland, April; Eriksson, Stefan; Evans, A.; Evetts, N.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Grandemange, P.; Granum, P.; Hangst, J. S.; Hardy, W. N.; Hayden, M. E.; Hodgkinson, D.; Hunter, E.; Isaac, Aled; Johnson, M. A.; Jones, J. M.; Jones, S. A.; Jonsell, S.; Khramov, A.; Knapp, P.; Kurchaninov, L.; Madsen, Niels; Maxwell, D.; K., J. T.; Menary, S.; Michan, J. M.; Momose, T.; Mullan, Patrick; Munich, J. J.; Olchanski, K.; Olin, A.; Peszka, J.; Powell, A.; Pusa, P.; Rasmussen, C. Ø.; Robicheaux, F.; Sacramento, R. L.; Sameed, M.; Sarid, E.; Silveira, D. M.; Starko, D. M.; So, C.; Stutter, G.; Tharp, T. D.; Thibeault, A.; Thompson, R. I.; der, Dirk van; Wurtele, J. S.; Charlton, Michael

doi:10.1038/s41586-021-03289-6

Journal article 986 views 85 downloads

Laser cooling of antihydrogen atoms

Christopher Baker

, W. Bertsche, A. Capra, C. Carruth, C. L. Cesar, M. Charlton, A. Christensen, R. Collister, April Cridland

, Stefan Eriksson

, A. Evans, N. Evetts, J. Fajans

, T. Friesen, M. C. Fujiwara

, D. R. Gill, P. Grandemange, P. Granum

, J. S. Hangst, W. N. Hardy, M. E. Hayden, D. Hodgkinson, E. Hunter, Aled Isaac

, M. A. Johnson, J. M. Jones, S. A. Jones, S. Jonsell

, A. Khramov

, P. Knapp, L. Kurchaninov, Niels Madsen

, D. Maxwell, J. T. K. McKenna, S. Menary, J. M. Michan, T. Momose, Patrick Mullan, J. J. Munich

, K. Olchanski, A. Olin

, J. Peszka

, A. Powell, P. Pusa, C. Ø. Rasmussen

, F. Robicheaux

, R. L. Sacramento, M. Sameed, E. Sarid, D. M. Silveira, D. M. Starko, C. So, G. Stutter, T. D. Tharp, A. Thibeault, R. I. Thompson, Dirk van der Werf

, J. S. Wurtele

, Michael Charlton

Nature, Volume: 592, Issue: 7852, Pages: 35 - 42

Swansea University Authors: Christopher Baker , April Cridland , Stefan Eriksson , Aled Isaac , Niels Madsen , Patrick Mullan, Dirk van der Werf , Michael Charlton

PDF | Version of Record

© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License
Download (3.66MB)

Check full text

DOI (Published version): 10.1038/s41586-021-03289-6

Abstract

The photon—the quantum excitation of the electromagnetic field—is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40...

Full description

Published in:	Nature
ISSN:	0028-0836 1476-4687
Published:	Springer Science and Business Media LLC 2021
Online Access:	Check full text
URI:	https://cronfa.swan.ac.uk/Record/cronfa56625
Tags:	Add Tag No Tags, Be the first to tag this record!

first_indexed	2021-08-16T20:15:22Z
last_indexed	2023-01-11T14:35:58Z
id	cronfa56625
recordtype	SURis
fullrecord	<?xml version="1.0"?><rfc1807><datestamp>2022-11-09T15:21:14.5622824</datestamp><bib-version>v2</bib-version><id>56625</id><entry>2021-04-06</entry><title>Laser cooling of antihydrogen atoms</title><swanseaauthors><author><sid>0c72afb63bd0c6089fc5b60bd096103e</sid><ORCID>0000-0002-9448-8419</ORCID><firstname>Christopher</firstname><surname>Baker</surname><name>Christopher Baker</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>e3c734cfda1e0b3835968762f39525cc</sid><ORCID>0000-0003-4361-0266</ORCID><firstname>April</firstname><surname>Cridland</surname><name>April Cridland</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>785cbd474febb1bfa9c0e14abaf9c4a8</sid><ORCID>0000-0002-5390-1879</ORCID><firstname>Stefan</firstname><surname>Eriksson</surname><name>Stefan Eriksson</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>06d7ed42719ef7bb697cf780c63e26f0</sid><ORCID>0000-0002-7813-1903</ORCID><firstname>Aled</firstname><surname>Isaac</surname><name>Aled Isaac</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>e348e4d768ee19c1d0c68ce3a66d6303</sid><ORCID>0000-0002-7372-0784</ORCID><firstname>Niels</firstname><surname>Madsen</surname><name>Niels Madsen</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>d5167e8661859aff63e7984b1a421667</sid><firstname>Patrick</firstname><surname>Mullan</surname><name>Patrick Mullan</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>4a4149ebce588e432f310f4ab44dd82a</sid><ORCID>0000-0001-5436-5214</ORCID><firstname>Dirk</firstname><surname>van der Werf</surname><name>Dirk van der Werf</name><active>true</active><ethesisStudent>false</ethesisStudent></author><author><sid>d9099cdd0f182eb9a1c8fc36ed94f53f</sid><firstname>Michael</firstname><surname>Charlton</surname><name>Michael Charlton</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2021-04-06</date><deptcode>SPH</deptcode><abstract>The photon—the quantum excitation of the electromagnetic field—is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6,7,8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S–2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude—with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S–2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11,12,13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.</abstract><type>Journal Article</type><journal>Nature</journal><volume>592</volume><journalNumber>7852</journalNumber><paginationStart>35</paginationStart><paginationEnd>42</paginationEnd><publisher>Springer Science and Business Media LLC</publisher><placeOfPublication/><isbnPrint/><isbnElectronic/><issnPrint>0028-0836</issnPrint><issnElectronic>1476-4687</issnElectronic><keywords/><publishedDay>1</publishedDay><publishedMonth>4</publishedMonth><publishedYear>2021</publishedYear><publishedDate>2021-04-01</publishedDate><doi>10.1038/s41586-021-03289-6</doi><url/><notes/><college>COLLEGE NANME</college><department>Physics</department><CollegeCode>COLLEGE CODE</CollegeCode><DepartmentCode>SPH</DepartmentCode><institution>Swansea University</institution><apcterm/><funders>This work was supported by: the European Research Council through its Advanced Grant programme (JSH); CNPq, FAPERJ, RENAFAE (Brazil); NSERC, CFI, NRC/TRIUMF, EHPDS/EHDRS (Canada); FNU (Nice Centre), Carlsberg Foundation (Denmark); ISF (Israel); STFC, EPSRC, the Royal Society and the Leverhulme Trust (UK); DOE, NSF (USA); and VR (Sweden).</funders><projectreference/><lastEdited>2022-11-09T15:21:14.5622824</lastEdited><Created>2021-04-06T09:13:21.6433396</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Biosciences, Geography and Physics - Physics</level></path><authors><author><firstname>Christopher</firstname><surname>Baker</surname><orcid>0000-0002-9448-8419</orcid><order>1</order></author><author><firstname>W.</firstname><surname>Bertsche</surname><order>2</order></author><author><firstname>A.</firstname><surname>Capra</surname><order>3</order></author><author><firstname>C.</firstname><surname>Carruth</surname><order>4</order></author><author><firstname>C. L.</firstname><surname>Cesar</surname><order>5</order></author><author><firstname>M.</firstname><surname>Charlton</surname><order>6</order></author><author><firstname>A.</firstname><surname>Christensen</surname><order>7</order></author><author><firstname>R.</firstname><surname>Collister</surname><order>8</order></author><author><firstname>April</firstname><surname>Cridland</surname><orcid>0000-0003-4361-0266</orcid><order>9</order></author><author><firstname>Stefan</firstname><surname>Eriksson</surname><orcid>0000-0002-5390-1879</orcid><order>10</order></author><author><firstname>A.</firstname><surname>Evans</surname><order>11</order></author><author><firstname>N.</firstname><surname>Evetts</surname><order>12</order></author><author><firstname>J.</firstname><surname>Fajans</surname><orcid>0000-0002-4403-6027</orcid><order>13</order></author><author><firstname>T.</firstname><surname>Friesen</surname><order>14</order></author><author><firstname>M. C.</firstname><surname>Fujiwara</surname><orcid>0000-0002-9371-4904</orcid><order>15</order></author><author><firstname>D. R.</firstname><surname>Gill</surname><order>16</order></author><author><firstname>P.</firstname><surname>Grandemange</surname><order>17</order></author><author><firstname>P.</firstname><surname>Granum</surname><orcid>0000-0002-2710-266x</orcid><order>18</order></author><author><firstname>J. S.</firstname><surname>Hangst</surname><order>19</order></author><author><firstname>W. N.</firstname><surname>Hardy</surname><order>20</order></author><author><firstname>M. E.</firstname><surname>Hayden</surname><order>21</order></author><author><firstname>D.</firstname><surname>Hodgkinson</surname><order>22</order></author><author><firstname>E.</firstname><surname>Hunter</surname><order>23</order></author><author><firstname>Aled</firstname><surname>Isaac</surname><orcid>0000-0002-7813-1903</orcid><order>24</order></author><author><firstname>M. A.</firstname><surname>Johnson</surname><order>25</order></author><author><firstname>J. M.</firstname><surname>Jones</surname><order>26</order></author><author><firstname>S. A.</firstname><surname>Jones</surname><order>27</order></author><author><firstname>S.</firstname><surname>Jonsell</surname><orcid>0000-0003-4969-1714</orcid><order>28</order></author><author><firstname>A.</firstname><surname>Khramov</surname><orcid>0000-0001-7218-8549</orcid><order>29</order></author><author><firstname>P.</firstname><surname>Knapp</surname><order>30</order></author><author><firstname>L.</firstname><surname>Kurchaninov</surname><order>31</order></author><author><firstname>Niels</firstname><surname>Madsen</surname><orcid>0000-0002-7372-0784</orcid><order>32</order></author><author><firstname>D.</firstname><surname>Maxwell</surname><order>33</order></author><author><firstname>J. T. K.</firstname><surname>McKenna</surname><order>34</order></author><author><firstname>S.</firstname><surname>Menary</surname><order>35</order></author><author><firstname>J. M.</firstname><surname>Michan</surname><order>36</order></author><author><firstname>T.</firstname><surname>Momose</surname><order>37</order></author><author><firstname>Patrick</firstname><surname>Mullan</surname><order>38</order></author><author><firstname>J. J.</firstname><surname>Munich</surname><orcid>0000-0001-7475-3070</orcid><order>39</order></author><author><firstname>K.</firstname><surname>Olchanski</surname><order>40</order></author><author><firstname>A.</firstname><surname>Olin</surname><orcid>0000-0001-8055-7180</orcid><order>41</order></author><author><firstname>J.</firstname><surname>Peszka</surname><orcid>0000-0002-5140-8079</orcid><order>42</order></author><author><firstname>A.</firstname><surname>Powell</surname><order>43</order></author><author><firstname>P.</firstname><surname>Pusa</surname><order>44</order></author><author><firstname>C. Ø.</firstname><surname>Rasmussen</surname><orcid>0000-0002-6029-1730</orcid><order>45</order></author><author><firstname>F.</firstname><surname>Robicheaux</surname><orcid>0000-0002-8054-6040</orcid><order>46</order></author><author><firstname>R. L.</firstname><surname>Sacramento</surname><order>47</order></author><author><firstname>M.</firstname><surname>Sameed</surname><order>48</order></author><author><firstname>E.</firstname><surname>Sarid</surname><order>49</order></author><author><firstname>D. M.</firstname><surname>Silveira</surname><order>50</order></author><author><firstname>D. M.</firstname><surname>Starko</surname><order>51</order></author><author><firstname>C.</firstname><surname>So</surname><order>52</order></author><author><firstname>G.</firstname><surname>Stutter</surname><order>53</order></author><author><firstname>T. D.</firstname><surname>Tharp</surname><order>54</order></author><author><firstname>A.</firstname><surname>Thibeault</surname><order>55</order></author><author><firstname>R. I.</firstname><surname>Thompson</surname><order>56</order></author><author><firstname>Dirk</firstname><surname>van der Werf</surname><orcid>0000-0001-5436-5214</orcid><order>57</order></author><author><firstname>J. S.</firstname><surname>Wurtele</surname><orcid>0000-0001-8401-0297</orcid><order>58</order></author><author><firstname>Michael</firstname><surname>Charlton</surname><order>59</order></author></authors><documents><document><filename>56625__19748__64c82454722445cdbca6ce04100fe0c5.pdf</filename><originalFilename>56625.pdf</originalFilename><uploaded>2021-04-23T16:51:20.5584225</uploaded><type>Output</type><contentLength>3836231</contentLength><contentType>application/pdf</contentType><version>Version of Record</version><cronfaStatus>true</cronfaStatus><documentNotes>© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License</documentNotes><copyrightCorrect>true</copyrightCorrect><language>eng</language><licence>http://creativecommons.org/licenses/by/4.0/</licence></document></documents><OutputDurs/></rfc1807>
spelling	2022-11-09T15:21:14.5622824 v2 56625 2021-04-06 Laser cooling of antihydrogen atoms 0c72afb63bd0c6089fc5b60bd096103e 0000-0002-9448-8419 Christopher Baker Christopher Baker true false e3c734cfda1e0b3835968762f39525cc 0000-0003-4361-0266 April Cridland April Cridland true false 785cbd474febb1bfa9c0e14abaf9c4a8 0000-0002-5390-1879 Stefan Eriksson Stefan Eriksson true false 06d7ed42719ef7bb697cf780c63e26f0 0000-0002-7813-1903 Aled Isaac Aled Isaac true false e348e4d768ee19c1d0c68ce3a66d6303 0000-0002-7372-0784 Niels Madsen Niels Madsen true false d5167e8661859aff63e7984b1a421667 Patrick Mullan Patrick Mullan true false 4a4149ebce588e432f310f4ab44dd82a 0000-0001-5436-5214 Dirk van der Werf Dirk van der Werf true false d9099cdd0f182eb9a1c8fc36ed94f53f Michael Charlton Michael Charlton true false 2021-04-06 SPH The photon—the quantum excitation of the electromagnetic field—is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6,7,8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S–2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude—with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S–2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11,12,13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules. Journal Article Nature 592 7852 35 42 Springer Science and Business Media LLC 0028-0836 1476-4687 1 4 2021 2021-04-01 10.1038/s41586-021-03289-6 COLLEGE NANME Physics COLLEGE CODE SPH Swansea University This work was supported by: the European Research Council through its Advanced Grant programme (JSH); CNPq, FAPERJ, RENAFAE (Brazil); NSERC, CFI, NRC/TRIUMF, EHPDS/EHDRS (Canada); FNU (Nice Centre), Carlsberg Foundation (Denmark); ISF (Israel); STFC, EPSRC, the Royal Society and the Leverhulme Trust (UK); DOE, NSF (USA); and VR (Sweden). 2022-11-09T15:21:14.5622824 2021-04-06T09:13:21.6433396 Faculty of Science and Engineering School of Biosciences, Geography and Physics - Physics Christopher Baker 0000-0002-9448-8419 1 W. Bertsche 2 A. Capra 3 C. Carruth 4 C. L. Cesar 5 M. Charlton 6 A. Christensen 7 R. Collister 8 April Cridland 0000-0003-4361-0266 9 Stefan Eriksson 0000-0002-5390-1879 10 A. Evans 11 N. Evetts 12 J. Fajans 0000-0002-4403-6027 13 T. Friesen 14 M. C. Fujiwara 0000-0002-9371-4904 15 D. R. Gill 16 P. Grandemange 17 P. Granum 0000-0002-2710-266x 18 J. S. Hangst 19 W. N. Hardy 20 M. E. Hayden 21 D. Hodgkinson 22 E. Hunter 23 Aled Isaac 0000-0002-7813-1903 24 M. A. Johnson 25 J. M. Jones 26 S. A. Jones 27 S. Jonsell 0000-0003-4969-1714 28 A. Khramov 0000-0001-7218-8549 29 P. Knapp 30 L. Kurchaninov 31 Niels Madsen 0000-0002-7372-0784 32 D. Maxwell 33 J. T. K. McKenna 34 S. Menary 35 J. M. Michan 36 T. Momose 37 Patrick Mullan 38 J. J. Munich 0000-0001-7475-3070 39 K. Olchanski 40 A. Olin 0000-0001-8055-7180 41 J. Peszka 0000-0002-5140-8079 42 A. Powell 43 P. Pusa 44 C. Ø. Rasmussen 0000-0002-6029-1730 45 F. Robicheaux 0000-0002-8054-6040 46 R. L. Sacramento 47 M. Sameed 48 E. Sarid 49 D. M. Silveira 50 D. M. Starko 51 C. So 52 G. Stutter 53 T. D. Tharp 54 A. Thibeault 55 R. I. Thompson 56 Dirk van der Werf 0000-0001-5436-5214 57 J. S. Wurtele 0000-0001-8401-0297 58 Michael Charlton 59 56625__19748__64c82454722445cdbca6ce04100fe0c5.pdf 56625.pdf 2021-04-23T16:51:20.5584225 Output 3836231 application/pdf Version of Record true © The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License true eng http://creativecommons.org/licenses/by/4.0/
title	Laser cooling of antihydrogen atoms
spellingShingle	Laser cooling of antihydrogen atoms Christopher Baker April Cridland Stefan Eriksson Aled Isaac Niels Madsen Patrick Mullan Dirk van der Werf Michael Charlton
title_short	Laser cooling of antihydrogen atoms
title_full	Laser cooling of antihydrogen atoms
title_fullStr	Laser cooling of antihydrogen atoms
title_full_unstemmed	Laser cooling of antihydrogen atoms
title_sort	Laser cooling of antihydrogen atoms
author_id_str_mv	0c72afb63bd0c6089fc5b60bd096103e e3c734cfda1e0b3835968762f39525cc 785cbd474febb1bfa9c0e14abaf9c4a8 06d7ed42719ef7bb697cf780c63e26f0 e348e4d768ee19c1d0c68ce3a66d6303 d5167e8661859aff63e7984b1a421667 4a4149ebce588e432f310f4ab44dd82a d9099cdd0f182eb9a1c8fc36ed94f53f
author_id_fullname_str_mv	0c72afb63bd0c6089fc5b60bd096103e_*_Christopher Baker e3c734cfda1e0b3835968762f39525cc__April Cridland 785cbd474febb1bfa9c0e14abaf9c4a8__Stefan Eriksson 06d7ed42719ef7bb697cf780c63e26f0__Aled Isaac e348e4d768ee19c1d0c68ce3a66d6303__Niels Madsen d5167e8661859aff63e7984b1a421667__Patrick Mullan 4a4149ebce588e432f310f4ab44dd82a__Dirk van der Werf d9099cdd0f182eb9a1c8fc36ed94f53f_*_Michael Charlton
author	Christopher Baker April Cridland Stefan Eriksson Aled Isaac Niels Madsen Patrick Mullan Dirk van der Werf Michael Charlton
author2	Christopher Baker W. Bertsche A. Capra C. Carruth C. L. Cesar M. Charlton A. Christensen R. Collister April Cridland Stefan Eriksson A. Evans N. Evetts J. Fajans T. Friesen M. C. Fujiwara D. R. Gill P. Grandemange P. Granum J. S. Hangst W. N. Hardy M. E. Hayden D. Hodgkinson E. Hunter Aled Isaac M. A. Johnson J. M. Jones S. A. Jones S. Jonsell A. Khramov P. Knapp L. Kurchaninov Niels Madsen D. Maxwell J. T. K. McKenna S. Menary J. M. Michan T. Momose Patrick Mullan J. J. Munich K. Olchanski A. Olin J. Peszka A. Powell P. Pusa C. Ø. Rasmussen F. Robicheaux R. L. Sacramento M. Sameed E. Sarid D. M. Silveira D. M. Starko C. So G. Stutter T. D. Tharp A. Thibeault R. I. Thompson Dirk van der Werf J. S. Wurtele Michael Charlton
format	Journal article
container_title	Nature
container_volume	592
container_issue	7852
container_start_page	35
publishDate	2021
institution	Swansea University
issn	0028-0836 1476-4687
doi_str_mv	10.1038/s41586-021-03289-6
publisher	Springer Science and Business Media LLC
college_str	Faculty of Science and Engineering
hierarchytype
hierarchy_top_id	facultyofscienceandengineering
hierarchy_top_title	Faculty of Science and Engineering
hierarchy_parent_id	facultyofscienceandengineering
hierarchy_parent_title	Faculty of Science and Engineering
department_str	School of Biosciences, Geography and Physics - Physics{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Biosciences, Geography and Physics - Physics
document_store_str	1
active_str	0
description	The photon—the quantum excitation of the electromagnetic field—is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6,7,8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S–2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude—with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S–2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11,12,13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.
published_date	2021-04-01T04:11:43Z
_version_	1763753803743494144
score	11.017797

Laser cooling of antihydrogen atoms

Similar Items