Nägerl, Hanns; Kraemer, Tobias; Mark, Michael; Waldburger, Philipp; Danzl, Johann GIST Austria ; Engeser, Bastian; Lange, Adam; Pilch, Karl; Jaakkola, Antti; Chin, Cheng; Grimm, Rudolf
Three interacting particles form a system which is well known for its complex physical behavior. A landmark theoretical result in few-body quantum physics is Efimov\'s prediction of a universal set of weakly bound trimer states appearing for three identical bosons with a resonant two-body interaction [1, 2]. Surprisingly, these states even exist in the absence of a corresponding two-body bound state and their precise nature is largely independent of the particular type of the two-body interaction potential. Efimov\'s scenario has attracted great interest in many areas of physics; an experimental test however has not been achieved. We report the observation of an Efimov resonance in an ultracold thermal gas of cesium atoms . The resonance occurs in the range of large negative two-body scattering lengths and arises from the coupling of three free atoms to an Efimov trimer. We observe its signature as a giant three-body recombination loss when the strength of the two-body interaction is varied near a Feshbach resonance. This resonance develops into a continuum resonance at non-zero collision energies, and we observe a shift of the resonance position as a function of temperature. We also report on a minimum in the recombination loss for positive scattering lengths, indicating destructive interference of decay pathways. Our results confirm central theoretical predictions of Efimov physics and represent a starting point from which to explore the universal properties of resonantly interacting few-body systems.
We thank E. Braaten, C. Greene, B. Esry, H. Hammer, and T. Köhl er for many stimulat- ing and fruitful discussions and E. Kneringer for support re garding the data analysis. We acknowledge support by the Austrian Science Fund (FWF) with in Spezialforschungs- bereich 15 and within the Lise Meitner program, and by the Eur opean Union in the frame of the TMR networks “Cold Molecules” and “FASTNet”. M.M. is s upported within the Doktorandenprogramm of the Austrian Academy of Sciences.
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ICAP: International Conference on Atomic Physics
Nägerl H, Kraemer T, Mark M, et al. Experimental evidence for Efimov quantum states. In: Vol 869. AIP; 2006:269-277. doi:10.1063/1.2400657
Nägerl, H., Kraemer, T., Mark, M., Waldburger, P., Danzl, J. G., Engeser, B., … Grimm, R. (2006). Experimental evidence for Efimov quantum states (Vol. 869, pp. 269–277). Presented at the ICAP: International Conference on Atomic Physics, AIP. https://doi.org/10.1063/1.2400657
Nägerl, Hanns, Tobias Kraemer, Michael Mark, Philipp Waldburger, Johann G Danzl, Bastian Engeser, Adam Lange, et al. “Experimental Evidence for Efimov Quantum States,” 869:269–77. AIP, 2006. https://doi.org/10.1063/1.2400657.
H. Nägerl et al., “Experimental evidence for Efimov quantum states,” presented at the ICAP: International Conference on Atomic Physics, 2006, vol. 869, pp. 269–277.
Nägerl H, Kraemer T, Mark M, Waldburger P, Danzl JG, Engeser B, Lange A, Pilch K, Jaakkola A, Chin C, Grimm R. 2006. Experimental evidence for Efimov quantum states. ICAP: International Conference on Atomic Physics vol. 869, 269–277.
Nägerl, Hanns, et al. Experimental Evidence for Efimov Quantum States. Vol. 869, AIP, 2006, pp. 269–77, doi:10.1063/1.2400657.