مكثف بوز-أينشتاين
إحصاء الجسيمات |
---|
إحصاء ماكسويل–بولتسمان |
إحصاء بوز–أينشتاين |
إحصاء فرمي–ديراك |
Parastatistics |
Anyonic statistics |
Braid statistics |
عدِّل |
مكثـَّـف بوز-أينشتاين (بالإنگليزية: Bose-Einstein Condensate) هي مادة تتصرف بطريقة غير طبيعية فقط عند درجات حرارة شديدة الإنخفاض، من الممكن عند كسر من البليون من درجة فوق الصفر المطلق. وعند تلك النقطة تصبح قوانين الثرموديناميكا هامة جداً.
النظرية
حيث:
-
is the critical temperature, is the particle density, is the mass per boson, is Planck's constant, is the Boltzmann constant, and is the Riemann zeta function;
دفوعات أينشتاين
للقيم الكبيرة من N ، فإن ثابت الـnormalization C هو(1-p). العدد الإجمالي المتسقط للجسيمات اللائي لسن في حالة أقل طاقة، في النهاية التي , is equal to . It doesn't grow when N is large, it just approaches a constant. This will be a negligible fraction of the total number of particles. So a collection of enough bose particles in thermal equilibrium will mostly be in the ground state, with only a few in any excited state, no matter how small the energy difference.
مخطط بيانات توزيع السرعة
الدوامات
الخصائص عير المعتادة
طالع أيضاً
|
|
المصادر
- Bose, S. N. (1924). "Plancks Gesetz und Lichtquantenhypothese". Zeitschrift für Physik. 26: 178. doi:10.1007/BF01327326.
- Einstein, A. (1925). "Quantentheorie des einatomigen idealen Gases". Sitzungsberichte der Preussischen Akademie der Wissenschaften. 1: 3.,
- Landau, L. D. (1941). "The theory of Superfluity of Helium 111". J. Phys. USSR. 5: 71–90.
- L. Landau (1941). "Theory of the Superfluidity of Helium II". Physical Review. 60: 356–358. doi:10.1103/PhysRev.60.356.
- M.H. Anderson, J.R. Ensher, M.R. Matthews, C.E. Wieman, and E.A. Cornell (1995). "Observation of Bose–Einstein Condensation in a Dilute Atomic Vapor". Science. 269: 198–201. doi:10.1126/science.269.5221.198. PMID 17789847.CS1 maint: multiple names: authors list (link)
- C. Barcelo, S. Liberati and M. Visser (2001). "Analogue gravity from Bose-Einstein condensates". Classical and Quantum Gravity. 18: 1137–1156. doi:10.1088/0264-9381/18/6/312.
- P.G. Kevrekidis, R. Carretero-Gonzlaez, D.J. Frantzeskakis and I.G. Kevrekidis (2006). "Vortices in Bose-Einstein Condensates: Some Recent Developments". Modern Physics Letters B. 5 (33).CS1 maint: multiple names: authors list (link)
- K.B. Davis, M.-O. Mewes, M.R. Andrews, N.J. van Druten, D.S. Durfee, D.M. Kurn, and W. Ketterle (1995). "Bose–Einstein condensation in a gas of sodium atoms". Physical Review Letters. 75: 3969–3973. doi:10.1103/PhysRevLett.75.3969.CS1 maint: multiple names: authors list (link).
- D. S. Jin, J. R. Ensher, M. R. Matthews, C. E. Wieman, and E. A. Cornell (1996). "Collective Excitations of a Bose–Einstein Condensate in a Dilute Gas". Physical Review Letters. 77: 420–423. doi:10.1103/PhysRevLett.77.420.CS1 maint: multiple names: authors list (link)
- M. R. Andrews, C. G. Townsend, H.-J. Miesner, D. S. Durfee, D. M. Kurn, and W. Ketterle (1997). "Observation of interference between two Bose condensates". Science. 275: 637–641. doi:10.1126/science.275.5300.637.CS1 maint: multiple names: authors list (link).
- Eric A. Cornell and Carl E. Wieman (1998). "The Bose-Einstein Condensate". Scientific American. 278 (3): 40–45.
- M. R. Matthews, B. P. Anderson, P. C. Haljan, D. S. Hall, C. E. Wieman, and E. A. Cornell (1999). "Vortices in a Bose–Einstein Condensate". Physical Review Letters. 83: 2498–2501. doi:10.1103/PhysRevLett.83.2498.CS1 maint: multiple names: authors list (link)
- E.A. Donley, N.R. Claussen, S.L. Cornish, J.L. Roberts, E.A. Cornell, and C.E. Wieman (2001). "Dynamics of collapsing and exploding Bose–Einstein condensates". Nature. 412: 295–299. doi:10.1038/35085500.CS1 maint: multiple names: authors list (link)
- M. Greiner, O. Mandel, T. Esslinger, T. W. Hänsch, I. Bloch (2002). "Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms". Nature. 415: 39–44. doi:10.1038/415039a.CS1 maint: multiple names: authors list (link).
- S. Jochim, M. Bartenstein, A. Altmeyer, G. Hendl, S. Riedl, C. Chin, J. Hecker Denschlag, and R. Grimm (2003). "Bose–Einstein Condensation of Molecules". Science. 302: 2101–2103. doi:10.1126/science.1093280.CS1 maint: multiple names: authors list (link)
- Markus Greiner, Cindy A. Regal and Deborah S. Jin (2003). "Emergence of a molecular Bose−Einstein condensate from a Fermi gas". Nature. 426: 537–540. doi:10.1038/nature02199.
- M. W. Zwierlein, C. A. Stan, C. H. Schunck, S. M. F. Raupach, S. Gupta, Z. Hadzibabic, and W. Ketterle (2003). "Observation of Bose–Einstein Condensation of Molecules". Physical Review Letters. 91: 250401. doi:10.1126/science.1093280.CS1 maint: multiple names: authors list (link)
- C. A. Regal, M. Greiner, and D. S. Jin (2004). "Observation of Resonance Condensation of Fermionic Atom Pairs". Physical Review Letters. 92: 040403. doi:10.1103/PhysRevLett.92.040403.CS1 maint: multiple names: authors list (link)
- C. J. Pethick and H. Smith, Bose–Einstein Condensation in Dilute Gases, Cambridge University Press, Cambridge, 2001.
- Lev P. Pitaevskii and S. Stringari, Bose–Einstein Condensation, Clarendon Press, Oxford, 2003.
- Amandine Aftalion, Vortices in Bose–Einstein Condensates, PNLDE Vol.67, Birkhauser, 2006.
- Mackie M, Suominen KA, Javanainen J., "Mean-field theory of Feshbach-resonant interactions in 85Rb condensates." Phys Rev Lett. 2002 Oct 28;89(18):180403.
الهامش
وصلات خارجية
- BEC Homepage General introduction to Bose–Einstein condensation
- Nobel Prize in Physics 2001 - for the achievement of Bose–Einstein condensation in dilute gases of alkali atoms, and for early fundamental studies of the properties of the condensates
- Physics Today: Cornell, Ketterle, and Wieman Share Nobel Prize for Bose–Einstein Condensates
- Bose–Einstein Condensates at JILA
- The Bose–Einstein Condensate at Utrecht University, the Netherlands
- Alkali Quantum Gases at MIT
- Atom Optics at UQ
- Einstein's manuscript on the Bose–Einstein condensate discovered at Leiden University
- The revolution that has not stopped PhysicsWeb article from June 2005
- Bose–Einstein condensate on arxiv.org
- Bosons - The Birds That Flock and Sing Together
- Oxford Experimental BEC Group.
- Cambridge University Cold Atoms Group.
- Easy BEC machine - information on constructing a Bose-Einstein condensate machine.
- Verging on absolute zero - Cosmos Online