[go: up one dir, main page]
Spring til indhold

Bruger:MellowMurmur/Lene Hau

Fra Wikipedia, den frie encyklopædi
MellowMurmur/Lene Hau
Lene Hau i sit laboratorium på Harvard, 2007
Personlig information
FødtLene Vestergaard Hau
13. november 1959 (64 år)
Vejle, Danmark
NationalitetDanmark
BopælBoston, USA
Uddannelse og virke
Uddannelses­stedAarhus Universitet
Forsknings­områdeFysik og Nanoteknologi
ArbejdsstedHarvard University, Rowland Institute for Science
Betydningsfulde eleverNaomi Ginsberg, Christopher Slowe, Zachary Dutton, Anne Goodsell, Trygve Ristrophe
Kendt forsit arbejde med lysets hastighed, Bose-Einstein-kondensaten, nanoteknologi og kvanteoptik
Nomineringer og priser
UdmærkelserOle Rømer-medaljen (2001)[1] George Ledlie Prize (2008)[2] Rigmor og Carl Holst-Knudsens Videnskabspris (2008)[3]

Lene Vestergaard Hau (født 1959) er en dansk forsker, med Ph.d. fra fysikstudiet på Aarhus Universitet. Hun startede som forskerassistent i USA og har efterfølgende arbejdet for Rowland Institute for Science, der er et forskningscenter i Boston. Hun er nu ansat som professor ved Harvard Universitet i instituttet for fysik.

Den 18. februar 1999 vakte hun international opsigt, da det lykkedes hende og hendes forskerteam at sænke lysets hastighed drastisk. Det lykkedes at bremse lysets hastighed fra 300.000 kilometer/sekund til 17 meter/sekund. Det blev gjort ved at køle en lille cigarformet sky af natriumatomer ned til en temperatur få milliontedele grad varmere end det absolutte nulpunkt på -273,15 grader. [4] [5]

I 2001 lykkedes det hende og hendes forskerteam at oplagre/stoppe en lyspuls, i en nedkølet sky af natriumatomer, ved hjælp at en koblingslaser. Når koblingslaseren lidt senere tændtes, genoptog den tidligere oplagrede lyspuls sin rejse ud af skyen. [6][7] [8] [9]

Den nedkølede sky af natriumatomer, anvendt ved begge forsøg, er faktisk i en ny fasetilstand ud over de kendte; fast, flydende, gasform, plasma, (neutronstjerne?, kvarkstjerne?) – nemlig Bose-Einstein kondensat. Atomerne i Bose-Einstein kondensatet (BEC) er kvantefysisk sammenfiltret, hvilket bl.a. har den effekt, at hele skyen virker som et stort atom.


Lene Vestergaard Hau (born in Vejle, Denmark, on November 13, 1959) is a Danish physicist. In 1999, she led a Harvard University team who, by use of a Bose-Einstein condensate, succeeded in slowing a beam of light to about 17 metres per second, and, in 2001, was able to stop a beam completely.[10] Later work based on these experiments led to the transfer of light to matter, then from matter back into light,[11] a process with important implications for quantum encryption and quantum computing.

Akademisk karriere

[redigér | rediger kildetekst]

Hau har en bachelorgrad i matematik fra 1984 og en kandidatgrad i fysik hos Aarhus Universitet fra 1986 . I hendes phd.-studier i kvantefysik har Hau arbejdet på idéer tilsvarende dem indenfor lysledende kabler - men hvor hendes arbejde involverede strenge af atomer i en atombærende silicon krystal. Under arbejdet på hendes doktorgrad, brugte Hau syv måneder ved CERN, det Europæiske Center for Forskning i Partikelfysik ved Geneve. Hun opnåede sin doktorgrad fra Aarhus Universitet i Denmark i 1991, og på dette tidspunkt havde hendes interesser i forskning skiftet retning. I 1991 sluttede hun sig til Rowland Institute for Science ved Cambridge som videnskabelig medarbejder, og begyndte at udforske mulighederne i langsomme og kolde atomer. I 1999 accepterede Hau en to-årig aftale som postdoc ved Harvard University. Hendes formelle uddannelse er i teoretisk fysik, men hendes interesse har bevæget sig mod eksperimentel forskning i en bestræbelse på at danne en ny form for stof kendt som Bose-Einstein-kondensat. Hau søgte midler hos National Science Foundation til at lave en en batch af kondensatet, men blev afvist, fordi hun var teoretiker, og experimentet derfor blev vurdere for svært for hende at udrette.[12] Ufortrødent fandt hun midler andetsteds, og blev en af de første af en håndfuld fysikere, der formåede at skabe et sådant kondensat. I september 1999 blev hun udnævnt til Gordon Mckay Professor i Anvendt Fysik og Professor i Fysik ved Harvard.[13] Hun blev tildelt uopsigelighed i 1999, og er nu Mallinckrodt Professor i Fysik og Anvendt Fysik ved Harvard. I 2001 blev hun den første person, der bremsede lys fuldkomment,[7] ved brug af Bose–Einstein-kondensat. Siden da har hun begået en stor mængde forskning og ny eksperimentelt arbejde i elektromagnetisk induceret transparens, flere områder indenfor kvantefysik, fotonik, har bidraget til udvikling af nye kvante-anordninger og nye nanoteknologiske applikationer.

I 2007 var Lene Hau med til gemme lysets information i stof og derefter ca. 0,14 μm væk konvertere stofinformationen til lysinformation igen. [14]

Hun modtog i 2010 Danes Worldwides årlige hædersbevis "Årets Verdensdansker" fordi hun ifølge Danes Worldwide eftertrykkeligt og vedholdende har sat Danmark på verdenskortet. [15]

Mere nyligt arbejde har involveret forskning i nye interactioner mellem ultrakolde atomer og nanoskopiske systemer. Udover at undervise i fysik og anvendt fysik, har hun undervist i Energy Science ved Harvard,[16] med emner som solceller, atomkraft, batterier and fotosyntese. Udover eksperimenter og forskning, holder hun foredrag ved internationale konferencer, og er involveret i udvikling af videnskabelige retningslinjer i diverse institutioner. Hun var hovedtaler[17] ved EliteForsk-konferencen 2013 i København den 7 februar 2013 med deltagelse fra ministre, samt senior videnskabspolitiske og forskningsmæssigt involverede fra Danmark.[18]

Qubit overførsel

[redigér | rediger kildetekst]

I 2006 formåede Hau og hendes kollegaer på Harvard University at overføre en qubit fra lys til en atomar bølge og tilbage til lys igen ved brug af Bose-Einstein kondensater.[19] Experimentet beror på, at atomer ifølge kvantemekanisk teori kan opføre sig som bølger så vel som partikler. Dette tillader atomer at gøre nogle ellers kontraintuitive ting så som at passere igennem to åbninger på samme tid. I et Bose-Einstein kondensat bliver en lyspuls komprimeret med en faktor på 50 millioner, uden at information i den bliver tabt. I dette Bose-Einstein kondensat, bliver informationen i lysimpulsen overført til atomare bølger, og fordi alle atomerne bevæger sig sammenhængende, bliver informationen ikke opløst i tilfældigt støj. Lyset får nogle af skyens ca. 1.8 millioner natrium-atomer til at gå ind i kvantesuperpositioner. En laser kan bruges til at forme en puls i de atomare bølger, og når denne laser slukkes, bevares en kopi i stoffet. Før dette var forskere ikke i stand til at styre optisk information under dets rejse udover ved at forstærke signalet for at undgå svind. Dette eksperiment af Hau og hendes kollegaer, markerer den første vellykkede manipulation af sammenhængende optisk information. Undersøgelsen har fået ros af Irina Novikova, fysiker ved College of William and Mary i Williamsburg, som bemærker: "Before this result, light storage was measured in milliseconds. Here it's fractional seconds. It's a really dramatic time."[20] – da.: Før dette resultat blev opbevaring a lys målt i millisekunder. Her er der tale om brøkdele af sekunder. Det er en virkelig markant tid.

Om forsøgets potentiale har Hau sagt: "While the matter is traveling between the two Bose–Einstein condensates, we can trap it, potentially for minutes, and reshape it – change it – in whatever way we want. This novel form of quantum control could also have applications in the developing fields of quantum information processing and quantum cryptography."[21] – da.: Når stoffet rejser mellem de to Bose-Einstein kondensater, kan vi fange det – måske i hele minutter – omforme det og ændre det som det passer os. Denne nye form for kvantekontrol kan måske også bruges i udvikling indenfor kvanteinformationsbehandling og kvantekryptografi. Om de udviklingsmæssige implikationer har Jeremy Bloxham – dekan for naturvidenskab i fakultetet for kunst og videnskab – sagt, “This feat, the sharing around of quantum information in light-form and in not just one but two atom-forms, offers great encouragement to those who hope to develop quantum computers,”[22] – da.: Denne bedrift – deling af kvanteinformation i lys og ikke bare en, men to atom-tilstande, er en stor opmuntring for dem, som håber på at udvikle kvantecomputere. Hau er blevet tildelt George Ledlie Prisen for dette stykke arbejde, og Harvard's prorektor – Steven Hyman – har bemærket, “her work is path-breaking. Her research blurs the boundaries between basic and applied science, draws on the talent and people of two Schools and several departments, and provides a literally glowing example of how taking daring intellectual risks leads to profound rewards.”[22] – da.: Hendes arbejde er banebrydende. Hendes forskning udvasker afgrænsningerne mellem grundforskning og anvendt videnskab, anvender talenter og folk fra to disclipliner og adskillige afdelinger, og er en bogstaveligt talt lysende eksempel på, at dristig intellektuel risikotagning kan lede til stor belønning.

Cold atoms and nanoscale systems

[redigér | rediger kildetekst]
A captured atom is ripped apart as its electron is sucked into the nanotube

In 2009 Hau and team laser-cooled clouds of one million rubidium atoms to just a fraction of a degree above absolute zero. They then launched this millimeter-long atomic cloud towards a suspended carbon nanotube, located some two centimeters away and charged to hundreds of volts. The results were published in 2010, heralding new interactions between cold atoms and nanoscale systems.[23] They observed that most atoms passed by, but approximately 10 per million were inescapably attracted, causing them to dramatically accelerate both movement and temperature. "At this point, the speeding atoms separate into an electron and an ion rotating in parallel around the nanowire, completing each orbit in just a few trillionths of a second. The electron eventually gets sucked into the nanotube via quantum tunneling, causing its companion ion to shoot away – repelled by the strong charge of the 300-volt nanotube – at a speed of roughly 26 kilometers per second, or 59,000 miles per hour."[24] Atoms can rapidly disintegrate, without having to collide with each other in this experiment. The team is quick to note that this effect is not produced by gravity, as calculated in blackholes that exist in space, but by the high electrical charge in the nanotube. The experiment combines nanotechnology with cold atoms to demonstrate a new type of high-resolution, single-atom, chip-integrated detector that may ultimately be able to resolve fringes from the interference of matter waves. The scientists also foresee a range of single-atom, fundamental studies made possible by their setup.[25]

Awards

[redigér | rediger kildetekst]

Publications

[redigér | rediger kildetekst]
  • Lene Vestergaard Hau, Manipulating Light[50] Unit 7 of the Annenberg Foundation's "Physics for the 21st Century"
  • Anne Goodsell, Trygve Ristroph, J. A. Golovchenko, and Lene Vestergaard Hau, Field ionization of cold atoms near the wall of a single carbon nanotube [23] (2010)
  • Rui Zhang, Sean R. Garner, and Lene Vestergaard Hau, Creation of long-term coherent optical memory via controlled nonlinear interactions in Bose–Einstein condensates [51] (2009)
  • Naomi S. Ginsberg, Sean R. Garner, and Lene Vestergaard Hau, Coherent control of optical information with matter wave dynamics[52] (2007).
  • Naomi S. Ginsberg, Joachim Brand, Lene Vestergaard Hau, Observation of Hybrid Soliton Vortex-Ring Structures in Bose–Einstein Condensates [53] (2005).
  • Chien Liu, Zachary Dutton, Cyrus H. Behroozi, Lene Vestergaard Hau, Observation of coherent optical information storage in an atomic medium using halted light pulses[54]
  • Lene Vestergaard Hau, S. E. Harris, Zachary Dutton, Cyrus H. Behroozi, Light speed reduction to 17 metres per second in an ultracold atomic gas[55]

Se også

[redigér | rediger kildetekst]
  • Kvantemekanik
  • Lene Vestergaard Hau, Quantum Optics: Slowing single photons[56]
  • Brian Murphy and Lene Vestergaard Hau, Electro-optical nanotraps for neutral atoms, [57]
  • Lene Vestergaard Hau, Optical information processing in Bose–Einstein condensates, [58]
  • Lene Vestergaard Hau, Quantum physics – Tangled memories, [59]
  • Lene Vestergaard Hau, Nonlinear optics: Shocking superfluids, [60]
  • Christopher Slowe, Laurent Vernac, Lene Vestergaard Hau, A High Flux Source of Cold Rubidium[61]
  • Christopher Slowe, Naomi S. Ginsberg, Trygve Ristroph, Anne Goodsell, and Lene Vestergaard Hau, Ultraslow Light & Bose–Einstein Condensates:Two-way Control with Coherent Light & Atom Fields [62]
  • Marin Soljacic, Elefterios Lidorikis, J. D. Joannopoulos, Lene Vestergaard Hau, Ultra Low-Power All-Optical Switching[63]
  • Trygve Ristroph, Anne Goodsell, J. A. Golovchenko, and Lene Vestergaard Hau, Detection and quantized conductance of neutral atoms near a charged carbon nanotube[64]
  • Zachary Dutton, Lene Vestergaard Hau, Storing and processing optical information with ultra-slow light in Bose–Einstein condensates[65]
  • Zachary Dutton, Naomi S. Ginsberg, Christopher Slowe, and Lene Vestergaard Hau, The Art of Taming Light: Ultra-slow and Stopped Light[66]
  • Lene Vestergaard Hau, Frozen Light [67]
  • Zachary Dutton, Michael Budde, Christopher Slowe, Lene Vestergaard Hau, Observation of quantum shock waves created with ultra-compressed slow light pulses in a Bose–Einstein Condensate[68]
  • Lene Vestergaard Hau, Taming Light with Cold Atoms[69] Invited feature article. Published by Institute for Physics, UK.
  • B. D. Busch, Chien Liu, Z. Dutton, C. H. Behroozi, L. Vestergaard Hau, Observation of interaction dynamics in finite-temperature Bose condensed atom clouds[70]
  • C. Liu, B.D. Busch, Z. Dutton, and L. V. Hau, Anisotropic Expansion of Finite Temperature Bose Gases – Emergence of Interaction Effects between Condensed and Non-Condensed Atoms,[71] Proceedings of the conference on New Directions in Atomic Physics, Cambridge, England, July 1998, eds. C. T. Whelan, R.M. Dreizler, J.H. Macek, and H.R.J Walters, (Plenum, 1999).
  • Lene Hau, BEC and Light Speeds of 38 miles/hr: Proceedings of the Workshop on Bose–Einstein Condensation and Degenerate Fermi Gases, from Workshop on Bose–Einstein Condensation and Degenerate Fermi Gases[72] Hau's talk: Podcast and image files.[73]
  • Lene Vestergaard Hau, B. D. Busch, Chien Liu, Zachary Dutton, Michael M. Burns, J. A. Golovchenko, Near Resonant Spatial Images of Confined Bose–Einstein Condensates in the 4-Dee Magnetic Bottle[74]
  • Lene Vestergaard Hau, B. D. Busch, Chien Liu, Michael M. Burns, J. A. Golovchenko, Cold Atoms and Creation of New States of Matter: Bose–Einstein Condensates, Kapitza States, and '2D Magnetic Hydrogen Atoms, (Photonic, Electronic and Atomic Collisions : Invited papers of the 20th International Conference of Electronic and Atomic Collisions (ICEAC) Vienna, Austria, July 23–29, 1997) F. Aumayr and H.P. Winter, editors[75]
  • Lene Vestergaard Hau, J. A. Golovchenko, and Michael M. Burns, Supersymmetry and the Binding of a Magnetic Atom to a Filamentary Current[76]
  • Lene Vestergaard Hau, J. A. Golovchenko, and Michael M. Burns, A new atomic beam source: The "candlestick" [77]
  • Lene Vestergaard Hau, Michael M. Burns, and J. A. Golovchenko, Bound states of guided matter waves: An atom and a charged wire [78]
  • "Absolute Zero and the Conquest of Cold"[79]
  • "Absolute Zero and the Conquest of Cold" Tom Schactman Pub Date: Dec. 1st, 1999 Publisher: Houghton Mifflin[80]

Kilder/henvisninger

[redigér | rediger kildetekst]
  1. ^ "Kalender over arrangementer".på DTU
  2. ^ "Ledlie Prize for research expected to improve fiber optics and computing".
  3. ^ "Rigmor og Carl Holst-Knudsens Videnskabspris". på Aarhus Universitet
  4. ^ Phillip F. Schewe, Ben Stein, "Light has been slowed to a speed of 17 meters/second ...," Physcis News Update, American Institute of Physics, nummer 415, 18. februar 1999.
  5. ^ OE Reports, Number 185, May 1999, Behind the mass-media story: Bose-Einstein condensate slows light
  6. ^ Chien Liu, Zachary Dutton, Cyrus H. Behroozi, Lene Vestergaard Hau, "Observation of coherent optical information storage in an atomic medium using halted light pulses," Nature 409:490-493, 25. januar 2001.
  7. ^ a b Physics Central – Lene Hau
  8. ^ BBC News: 18 January, 2001, Light stopped in its tracks Citat: "... And, astonishingly, if the coupling laser is turned off while the probe pulse is inside the gas cloud, the probe pulse stops dead in its tracks. If the coupling beam is then turned back on, the probe pulse emerges intact, just as if it had been waiting to resume its journey. The biggest impact of this work could be in the burgeoning field of quantum computing and quantum communication...."
  9. ^ Nature, 19 January 2001: Stop that light beam, I want to get off
  10. ^ a b "Lene Hau".
  11. ^ Coherent control of optical information with matter wave dynamics
  12. ^ "Hau wins MacArthur". (engelsk)
  13. ^ "Hau Receives Tenure; Physics Professor Slowed Light". (engelsk)
  14. ^ February 8, 2007 In Tiny Supercooled Clouds, Physicists Exchange Light And Matter Citat: "..."We demonstrate that we can stop a light pulse in a supercooled sodium cloud, store the data contained within it, and totally extinguish it, only to reincarnate the pulse in another cloud two-tenths of a millimeter away," says Lene Vestergaard Hau, Mallinckrodt Professor of Physics and of Applied Physics in Harvard's Faculty of Arts and Sciences and School of Engineering and Applied Sciences..."
  15. ^ Kvindelig lysgeni er Årets Verdensdansker – Danmark
  16. ^ "Physics 129. Energy Science | FAS Registrar's Office".
  17. ^ Eliteforsk Konferencen 2013 Billeder
  18. ^ We need more of investigator-microbe in the blood
  19. ^ GERDA – Aarhus Universitet's Alumnenetværk – Distinguished alum one of the 50 most influential scientists in the world
  20. ^ "Sanders, L. (2010), Matter & energy: Trapped in cloud of ultracold atoms, light stayed frozen for 1.5 seconds: Technique, if improved, could lead to light-storage devices. Science News, 177: 10. doi: 10.1002/scin.5591770209".
  21. ^ "Light Changed to Matter, Then Stopped and Moved".
  22. ^ a b "Hau awarded prestigious Ledlie".
  23. ^ a b "Field Ionization of Cold Atoms near the Wall of a Single Carbon Nanotube".
  24. ^ "Cold atoms and nanotubes come together in an atomic 'black hole'".
  25. ^ "Physics – Ionizing atoms with a nanotube".
  26. ^ "2011 honorary alum: Lene Vestergaard Hau".
  27. ^ "Hau Lab at Harvard".
  28. ^ "Videnskabernes Selskab".
  29. ^ Hans Christian Oersted Lecture, 16 September 2010:Quantum control of light and matter – from the macroscopic to the nanoscale
  30. ^ "Kvindelig lysgeni er Årets Verdensdansker".
  31. ^ "Meet the 2010 National Security Science & Engineering Faculty Fellows | Armed with Science".
  32. ^ "Hau, Lene Vestergaard (Danish scientist)".
  33. ^ "Lene Hau and condensed matter physics, transcript | AAAS MemberCentral".
  34. ^ Members List
  35. ^ "Hau biography".
  36. ^ Wizardry with Light: Freeze, Teleport, and Go!
  37. ^ "Rigmor og Carl Holst-Knudsens Videnskabspris".
  38. ^ "Ledlie Prize for research expected to improve fiber optics and computing".
  39. ^ "Richtmyer Memorial Lecture".
  40. ^ The Nano-Lectures: Lene Hau
  41. ^ Light at Bicycle Speed ...and Slower Yet!
  42. ^ Hau wins MacArthur
  43. ^ "128th National Meeting – Featured Speakers".
  44. ^ "Calendar of Events".
  45. ^ The year's honorary craftsman (Kjøbenhavns Craftsman Association)
  46. ^ "Hau Awards".
  47. ^ "Mobil: Topdanmark".
  48. ^ "Gordon McKay — Harvard School of Engineering and Applied Sciences".
  49. ^ "Absolute Zero and the Conquest of Cold".
  50. ^ Physics – Content by Unit
  51. ^ "Creation of Long-Term Coherent Optical Memory via Controlled Nonlinear Interactions in Bose–Einstein Condensates".
  52. ^ "Coherent control of optical information with matter wave dynamics".
  53. ^ "Observation of Hybrid Soliton Vortex-Ring Structures in Bose–Einstein Condensates".
  54. ^ Observation of coherent optical information storage in an atomic medium using halted light pulses
  55. ^ Light speed reduction to 17 metres per second in an ultracold atomic gas
  56. ^ Quantum Optics: Slowing single photons
  57. ^ Optical Nanotraps for Neutral Atoms
  58. ^ "Optical information processing in Bose–Einstein condensates".
  59. ^ Quantum physics – Tangled memories
  60. ^ Nonlinear optics: Shocking superfluids
  61. ^ A High Flux Source of Cold Rubidium
  62. ^ "Optics & Photonics News – Ultraslow Light & Bose–Einstein Condensates: Two-way Control with Coherent Light & Atom Fields".
  63. ^ Ultra Low-Power All-Optical Switching
  64. ^ "Detection and quantized conductance of neutral atoms near a charged carbon nanotube".
  65. ^ Storing and processing optical information with ultraslow light in Bose–Einstein condensates
  66. ^ The art of taming light: ultra-slow and stopped light | Europhysics News
  67. ^ Frozen Light: Scientific American and Special Scientific American Issue entitled "The Edge of Physics" (2003)
  68. ^ Observation of Quantum Shock Waves Created with Ultra- Compressed Slow Light Pulses in a Bose–Einstein Condensate
  69. ^ PhysicsWorld Archive » Volume 14 » Taming light with cold atoms
  70. ^ Observation of interaction dynamics in finite-temperature Bose condensed atom clouds
  71. ^ "Anisotropic Expansion of Finite Temperature Bose Gases — Emergence of Interaction Effects Between Condensed and Non-Condensed Atoms".
  72. ^ JILA Workshop on BEC and degenerate Fermi gases
  73. ^ Hau, February 1999 CTAMOP Workshop
  74. ^ Near-resonant spatial images of confined Bose–Einstein condensates in a 4-Dee magnetic bottle
  75. ^ Cold Atoms and Creation of New States of Matter: Bose–Einstein Condensates, Kapitza States, and '2D Magnetic Hydrogen Atoms
  76. ^ Phys. Rev. Lett. 74, 3138 (1995): Supersymmetry and the Binding of a Magnetic Atom to a Filamentary Current
  77. ^ A new atomic beam source: The "candlestick"
  78. ^ Phys. Rev. A 45, 6468 (1992): Bound states of guided matter waves: An atom and a charged wire
  79. ^ Documentary charting the progress of scientists throughout history who attempted to harness the ultimate limit of cold, known as absolute zero
  80. ^ Enter the realm of quantum mechanics, where superconductivity and superfluidity and the total absence of magnetism bends our perception of the material world.

Eksterne henvisninger

[redigér | rediger kildetekst]


Hentet fra "https://da.wikipedia.org/w/index.php?title=Bruger:MellowMurmur/Lene_Hau&oldid=8744836"