Laser cooling of larger quantum objects

doi:10.1126/science.abd1657

GSTDTAP > 气候变化

DOI	10.1126/science.abd1657
	Laser cooling of larger quantum objects
	Eric R. Hudson
	2020-09-11
发表期刊	Science
出版年	2020
英文摘要	Surfers have a concept they call progression. It is roughly the idea that each successive generation of wave riders is not constrained by the same idea of what is “impossible.” Progression often comes in small steps, usually helped by improvements in technology but every so often—like Laird Hamilton's Millennium Wave at Teahupoo, Tahiti ([ 1 ][1])—it comes in a giant leap when somebody does what everyone else was too scared to try. On page 1366 of this issue, Mitra et al. ([ 2 ][2]) have progressed molecular physics in a step that was unthinkable only a few years ago by laser-cooling a nonlinear polyatomic molecule, CaOCH3. Like stopping a bowling ball by repeatedly hitting it with ping-pong balls ([ 3 ][3]), laser cooling utilizes the repeated scattering of photons from a particle to cool it to ultracold temperatures (<1 mK). The technique, which garnered the 1997 Nobel Prize, has been the workhorse of atomic physics for roughly three decades and underlies virtually all experiments in the field, in areas as diverse as quantum computing and timekeeping. Extending the technique to more complicated objects such as diatomic and polyatomic molecules holds promise for new routes to important quantum science and technology ([ 4 ][4]). For atoms, their simple electronic structure enables their quick relaxation, through spontaneous emission, to only one of a few low-lying electronic states from which they can be re-excited. However, the ro-vibrational degrees of freedom of molecules lead to an increase in the number of low-energy states accessible by spontaneous emission. In general, scattering many photons from molecules requires an unwieldy number of lasers to address all of the possible low-lying ro-vibrational states. ![Figure][5] Choosing molecules for laser cooling A molecule can be laser-cooled if it absorbs and emits photons upon an electronic transition without changing its vibrational state. Mitra et al. have extended laser cooling from linear molecules to CaOCH3, a nonlinear polyatomic molecule. GRAPHIC: MELISSA THOMAS BAUM/ SCIENCE The beginning of a solution to this problem came in two steps. In 2004, Di Rosa ([ 5 ][6]) pointed out that certain diatomic molecules, whose atoms were bound by roughly the same force in their ground and excited electronic states, were unlikely to change their vibrational state when spontaneously emitting a photon (see the figure, top right). In 2008, Stuhl et al. ([ 6 ][7]) proposed a method, based on a so-called “type II” magneto-optical trap demonstrated in atoms ([ 7 ][8]) and only recently understood ([ 8 ][9]), to handle the pesky rotational degree of freedom. Less than a year later, Shuman et al. ([ 9 ][10]) provided the first experimental demonstration of these ideas on the molecule SrF. Since then, three-dimensional laser cooling and trapping have been demonstrated for a number of diatomics including CaF ([ 10 ][11], [ 11 ][12]), and laser cooling along one dimension has been observed in linear triatomic molecules such as SrOH ([ 12 ][13]). The choice of these molecules can be understood by considering their gross electronic structure ([ 13 ][14]). For example, in CaF and SrF, the ns2 configuration of the alkaline earth atom donates one electron to the halogen. The remaining valence electron remains localized on the metal such that the molecular electronic structure resembles that of the alkaline earth, making a nearly ideal molecule for laser cooling. If, however, O is used instead of F, the resulting electronic structure of CaO is markedly different from that of the parent metal atom and the molecule is a poor choice (see the figure, top left). Interestingly, the OH group in the triatomics behaves essentially like a halogen atom, accepting one electron from the ns2 configuration of the metal and yielding an atomic-like molecular electronic structure. Kozyryev et al. continued this trend of cooling larger, more complex molecules by showing that the methoxy group should also behave similarly to the halogen, and proposed CaOCH3 as a candidate for laser cooling (see the figure, bottom) ([ 14 ][15]). Although this choice may sound like a straightforward expansion, the extension to a nonlinear polyatomic molecule comes fraught with pitfalls. The spectroscopy of such molecules is much more complicated than the diatomics and triatomics studied previously. Effects normally neglected in smaller molecules can lead to a breakdown of the Born-Oppenheimer approximation and open new loss channels, such as coupling between the 12 vibrational modes of the molecule. Thus, like the Millennium Wave, the experiment had every chance of failure, but Mitra et al. demonstrated laser cooling of CaOCH3 along one dimension of a beam down to a temperature of ∼700 µK. They also demonstrated separate deterministic cooling of the two nuclear spin isomers. The immediate impact of this result is that we now know it is possible to laser-cool molecules with non- C ∞ v symmetry. This result opens the door to full three-dimensional cooling and trapping of a new class of quantum objects that possess previously inaccessible properties such as chirality. If the history of laser cooling is any guide, this capability should enable major advances in quantum computing and sensing, timekeeping, chemistry, and precision tests of fundamental physics ([ 15 ][16]). 1. [↵][17]Riding Giants, directed by Stacy Peralta (Studio Canal, 2004); excerpt at [www.youtube.com/watch?v=NcaZarxilJQ][18]. 2. [↵][19]1. D. Mitra, 2. N. B. Vilas, 3. C. Hallas, 4. L. Anderegg, 5. B. L. Augenbraun, 6. L. Baum, 7. C. Miller, 8. S. Raval, 9. J. M. Doyle , Science 369, 1366 (2020). [OpenUrl][20][Abstract/FREE Full Text][21] 3. [↵][22]1. W. D. Phillips , Rev. Mod. Phys. 70, 721 (1998). [OpenUrl][23][CrossRef][24][Web of Science][25] 4. [↵][26]1. M. R. Tarbutt , Contemp. Phys. 59, 356 (2019). [OpenUrl][27] 5. [↵][28]1. M. D. Di Rosa , Eur. Phys. J. D 31, 395 (2004). [OpenUrl][29] 6. [↵][30]1. B. K. Stuhl, 2. B. C. Sawyer, 3. D. Wang, 4. J. Ye , Phys. Rev. Lett. 101, 243002 (2008). [OpenUrl][31][PubMed][32] 7. [↵][33]1. E. L. Raab, 2. M. Prentiss, 3. A. Cable, 4. S. Chu, 5. D. E. Pritchard , Phys. Rev. Lett. 59, 2631 (1987). [OpenUrl][34][CrossRef][35][PubMed][36][Web of Science][37] 8. [↵][38]1. J. A. Devlin, 2. M. R. Tarbutt , New J. Phys. 18, 123017 (2016). [OpenUrl][39][CrossRef][40] 9. [↵][41]1. E. S. Shuman, 2. J. F. Barry, 3. D. R. Glenn, 4. D. DeMille , Phys. Rev. Lett. 103, 223001 (2009). [OpenUrl][42][PubMed][43] 10. [↵][44]1. S. Truppe, 2. H. J. Williams, 3. M. Hambach, 4. L. Caldwell, 5. N. J. Fitch, 6. E. A. Hinds, 7. B. E. Sauer, 8. M. R. Tarbutt , Nat. Phys. 13, 1173 (2017). [OpenUrl][45] 11. [↵][46]1. L. Anderegg, 2. B. L. Augenbraun, 3. E. Chae, 4. B. Hemmerling, 5. N. R. Hutzler, 6. A. Ravi, 7. A. Collopy, 8. J. Ye, 9. W. Ketterle, 10. J. M. Doyle , Phys. Rev. Lett. 119, 103201 (2017). [OpenUrl][47][CrossRef][48][PubMed][49] 12. [↵][50]1. I. Kozyryev, 2. L. Baum, 3. K. Matsuda, 4. B. L. Augenbraun, 5. L. Anderegg, 6. A. P. Sedlack, 7. J. M. Doyle , Phys. Rev. Lett. 118, 173201 (2017). [OpenUrl][51][CrossRef][52][PubMed][53] 13. [↵][54]1. T. A. Isaev, 2. R. Berger , Phys. Rev. Lett. 116, 063006 (2016). [OpenUrl][55][CrossRef][56][PubMed][57] 14. [↵][58]1. I. Kozyryev, 2. L. Baum, 3. K. Matsuda, 4. J. M. Doyle , ChemPhysChem 17, 3641 (2016). [OpenUrl][59][CrossRef][60][PubMed][61] 15. [↵][62]1. I. Kozyryev, 2. N. R. Hutzler , Phys. Rev. Lett. 119, 133002 (2017). [OpenUrl][63][CrossRef][64][PubMed][65] [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-4 [5]: pending:yes [6]: #ref-5 [7]: #ref-6 [8]: #ref-7 [9]: #ref-8 [10]: #ref-9 [11]: #ref-10 [12]: #ref-11 [13]: #ref-12 [14]: #ref-13 [15]: #ref-14 [16]: #ref-15 [17]: #xref-ref-1-1 "View reference 1 in text" [18]: http://www.youtube.com/watch?v=NcaZarxilJQ [19]: #xref-ref-2-1 "View reference 2 in text" [20]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DMitra%26rft.auinit1%253DD.%26rft.volume%253D369%26rft.issue%253D6509%26rft.spage%253D1366%26rft.epage%253D1369%26rft.atitle%253DDirect%2Blaser%2Bcooling%2Bof%2Ba%2Bsymmetric%2Btop%2Bmolecule%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.abc5357%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [21]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEzOiIzNjkvNjUwOS8xMzY2IjtzOjQ6ImF0b20iO3M6MjM6Ii9zY2kvMzY5LzY1MDkvMTMwNC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30= [22]: #xref-ref-3-1 "View reference 3 in text" [23]: {openurl}?query=rft.jtitle%253DReviews%2Bof%2BModern%2BPhysics%26rft.stitle%253DRev.%2BMod.%2BPhys.%26rft.aulast%253DPhillips%26rft.auinit1%253DW.%2BD.%26rft.volume%253D70%26rft.issue%253D3%26rft.spage%253D721%26rft.epage%253D742%26rft.atitle%253DLaser%2Bcooling%2Band%2Btrapping%2Bof%2Bneutral%2Batoms%26rft_id%253Dinfo%253Adoi%252F10.1103%252FRevModPhys.70.721%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [24]: /lookup/external-ref?access_num=10.1103/RevModPhys.70.721&link_type=DOI [25]: /lookup/external-ref?access_num=000075307800003&link_type=ISI [26]: #xref-ref-4-1 "View reference 4 in text" [27]: {openurl}?query=rft.jtitle%253DContemp.%2BPhys.%26rft.volume%253D59%26rft.spage%253D356%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [28]: #xref-ref-5-1 "View reference 5 in text" [29]: {openurl}?query=rft.jtitle%253DEur.%2BPhys.%2BJ.%2BD%26rft.volume%253D31%26rft.spage%253D395%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [30]: #xref-ref-6-1 "View reference 6 in text" [31]: {openurl}?query=rft.jtitle%253DPhysical%2BReview%2BLetters%26rft.stitle%253DPhysical%2BReview%2BLetters%26rft.aulast%253DStuhl%26rft.auinit1%253DB.%2BK.%26rft.volume%253D101%26rft.issue%253D24%26rft.spage%253D243002%26rft.epage%253D243002%26rft.atitle%253DMagneto-optical%2Btrap%2Bfor%2Bpolar%2Bmolecules.%26rft_id%253Dinfo%253Apmid%252F19113618%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [32]: /lookup/external-ref?access_num=19113618&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom [33]: #xref-ref-7-1 "View reference 7 in text" [34]: {openurl}?query=rft.jtitle%253DPhysical%2BReview%2BLetters%26rft.stitle%253DPhysical%2BReview%2BLetters%26rft.aulast%253DRaab%26rft.auinit1%253DE.%2BL.%26rft.volume%253D59%26rft.issue%253D23%26rft.spage%253D2631%26rft.epage%253D2634%26rft.atitle%253DTrapping%2Bof%2Bneutral%2Bsodium%2Batoms%2Bwith%2Bradiation%2Bpressure.%26rft_id%253Dinfo%253Adoi%252F10.1103%252FPhysRevLett.59.2631%26rft_id%253Dinfo%253Apmid%252F10035608%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [35]: /lookup/external-ref?access_num=10.1103/PhysRevLett.59.2631&link_type=DOI [36]: /lookup/external-ref?access_num=10035608&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom [37]: /lookup/external-ref?access_num=A1987L084400004&link_type=ISI [38]: #xref-ref-8-1 "View reference 8 in text" [39]: {openurl}?query=rft.jtitle%253DNew%2BJ.%2BPhys.%26rft.volume%253D18%26rft.spage%253D123017%26rft_id%253Dinfo%253Adoi%252F10.1088%252F1367-2630%252F18%252F12%252F123017%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [40]: /lookup/external-ref?access_num=10.1088/1367-2630/18/12/123017&link_type=DOI [41]: #xref-ref-9-1 "View reference 9 in text" [42]: {openurl}?query=rft.jtitle%253DPhysical%2BReview%2BLetters%26rft.stitle%253DPhysical%2BReview%2BLetters%26rft.aulast%253DShuman%26rft.auinit1%253DE.%2BS.%26rft.volume%253D103%26rft.issue%253D22%26rft.spage%253D223001%26rft.epage%253D223001%26rft.atitle%253DRadiative%2Bforce%2Bfrom%2Boptical%2Bcycling%2Bon%2Ba%2Bdiatomic%2Bmolecule.%26rft_id%253Dinfo%253Apmid%252F20366090%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [43]: /lookup/external-ref?access_num=20366090&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom [44]: #xref-ref-10-1 "View reference 10 in text" [45]: {openurl}?query=rft.jtitle%253DNat.%2BPhys.%26rft.volume%253D13%26rft.spage%253D1173%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [46]: #xref-ref-11-1 "View reference 11 in text" [47]: {openurl}?query=rft.jtitle%253DPhys.%2BRev.%2BLett.%26rft.volume%253D119%26rft.spage%253D103201%26rft_id%253Dinfo%253Adoi%252F10.1103%252FPhysRevLett.119.103201%26rft_id%253Dinfo%253Apmid%252F28949175%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [48]: /lookup/external-ref?access_num=10.1103/PhysRevLett.119.103201&link_type=DOI [49]: /lookup/external-ref?access_num=28949175&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom [50]: #xref-ref-12-1 "View reference 12 in text" [51]: {openurl}?query=rft.jtitle%253DPhys.%2BRev.%2BLett.%26rft.volume%253D118%26rft.spage%253D173201%26rft_id%253Dinfo%253Adoi%252F10.1103%252FPhysRevLett.118.173201%26rft_id%253Dinfo%253Apmid%252F28498706%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [52]: /lookup/external-ref?access_num=10.1103/PhysRevLett.118.173201&link_type=DOI [53]: /lookup/external-ref?access_num=28498706&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom [54]: #xref-ref-13-1 "View reference 13 in text" [55]: {openurl}?query=rft.jtitle%253DPhys.%2BRev.%2BLett.%26rft.volume%253D116%26rft.spage%253D063006%26rft_id%253Dinfo%253Adoi%252F10.1103%252FPhysRevLett.116.063006%26rft_id%253Dinfo%253Apmid%252F26918989%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [56]: /lookup/external-ref?access_num=10.1103/PhysRevLett.116.063006&link_type=DOI [57]: /lookup/external-ref?access_num=26918989&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom [58]: #xref-ref-14-1 "View reference 14 in text" [59]: {openurl}?query=rft.jtitle%253DChemPhysChem%26rft.volume%253D17%26rft.spage%253D3641%26rft_id%253Dinfo%253Adoi%252F10.1002%252Fcphc.201601051%26rft_id%253Dinfo%253Apmid%252F27759904%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [60]: /lookup/external-ref?access_num=10.1002/cphc.201601051&link_type=DOI [61]: /lookup/external-ref?access_num=27759904&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom [62]: #xref-ref-15-1 "View reference 15 in text" [63]: {openurl}?query=rft.jtitle%253DPhys.%2BRev.%2BLett.%26rft.volume%253D119%26rft.spage%253D133002%26rft_id%253Dinfo%253Adoi%252F10.1103%252FPhysRevLett.119.133002%26rft_id%253Dinfo%253Apmid%252F29341669%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [64]: /lookup/external-ref?access_num=10.1103/PhysRevLett.119.133002&link_type=DOI [65]: /lookup/external-ref?access_num=29341669&link_type=MED&atom=%2Fsci%2F369%2F6509%2F1304.atom
领域	气候变化 ; 资源环境
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引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/294089
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Eric R. Hudson. Laser cooling of larger quantum objects[J]. Science,2020.
APA	Eric R. Hudson.(2020).Laser cooling of larger quantum objects.Science.
MLA	Eric R. Hudson."Laser cooling of larger quantum objects".Science (2020).