| Autor: |
Jørgensen, Nils B., Wacker, Lars, Skalmstang, Kristoffer T., Parish, Meera M., Levinsen, Jesper, Christensen, Rasmus S., Bruun, Georg M., Arlt, Jan J. |
| Rok vydání: |
2016 |
| Předmět: |
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| Zdroj: |
Phys. Rev. Lett. 117, 055302 (2016) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevLett.117.055302 |
| Popis: |
The problem of an impurity particle moving through a bosonic medium plays a fundamental role in physics. However, the canonical scenario of a mobile impurity immersed in a Bose-Einstein condensate (BEC) has not yet been realized. Here, we use radio frequency spectroscopy of ultracold bosonic $^{39}$K atoms to experimentally demonstrate the existence of a well-defined quasiparticle state of an impurity interacting with a BEC. We measure the energy of the impurity both for attractive and repulsive interactions, and find excellent agreement with theories that incorporate three-body correlations, both in the weak-coupling limits and across unitarity. The spectral response consists of a well-defined quasiparticle peak at weak coupling, while for increasing interaction strength, the spectrum is strongly broadened and becomes dominated by the many-body continuum of excited states. Crucially, no significant effects of three-body decay are observed. Our results open up exciting prospects for studying mobile impurities in a bosonic environment and strongly interacting Bose systems in general. |
| Databáze: |
arXiv |
| Externí odkaz: |
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