Efimov effect

The Efimov effect is a solution to the quantum-mechanical three-body problem predicted by the Soviet theoretical physicist V. N. Efimov [В.И. Ефимов: Слабосвязанные состояния трех резонансно взаимодействующиnх частиц, Ядерная Физика, т. 12, вып. 5, 1080-1090, 1970 г.] [V. N. Efimov: Energy levels arising from resonant two-body forces in a three-body system. Phys. Lett. B, Vol. 33, Issue 8, p. 563-564. doi|10.1016/0370-2693(70)90349-7] in 1970. Efimov’s effect refers to a scenario in which three identical bosons interact, with the prediction of an infinite series of excited three-body energy levels when a two-body state is exactly at the dissociation threshold.One corollary is that three bosons can form a loosely bound system even if the two-particle attraction is too weak to allow two bosons to form a pair.

In 2006 scientists at Universität Innsbruck, Austria and at the University of Chicago in US reported [cite journal | author = T. Kraemer, M. Mark, P. Waldburger, J. G. Danzl, C. Chin, B. Engeser, A. D. Lange, K. Pilch, A. Jaakkola, H.-C. Nägerl and R. Grimm | title = Evidence for Efimov quantum states in an ultracold gas of caesium atoms | journal = Nature | volume = 440 | pages = 315–318 | doi = 10.1038/nature04626 | year = 2006] that they had detected Efimov states in scattering using caesium atoms at 10 nanokelvin. However, depending on the precise definition of an Efimov state (intersection or not with the two-body level when the pairwise attraction is modified) this report is sometimes refute [cite journal | author = M. D. Lee, T Köhler and P. S. Julienne | title = Excited Thomas-Efimov levels in ultracold gases | journal = Physical Review A | volume = 76 | pages = 012720 | doi = 10.1103/PhysRevA.76.012720 | year = 2007] .

References

External links

* [http://dx.doi.org/10.1016/0370-2693(70)90349-7 doi:10.1016/0370-2693(70)90349-7
*Kraemer "et al.": [http://arxiv.org/pdf/cond-mat/0512394 Evidence for Efimov quantum states in an ultracold gas of caesium atoms] at ArXiv.org.
* Lee "et al.": [http://fr.arxiv.org/abs/cond-mat/0702178 Excited Thomas-Efimov levels in ultracold gases] at ArXiv.org