Collective excitations of a degenerate gas at the BEC-BCS crossover

被引:511
作者
Bartenstein, M
Altmeyer, A
Riedl, S
Jochim, S
Chin, C
Denschlag, JH
Grimm, R
机构
[1] Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria
[2] Austrian Acad Sci, Inst Quantenopt & Quanteninformat, A-6020 Innsbruck, Austria
基金
奥地利科学基金会;
关键词
D O I
10.1103/PhysRevLett.92.203201
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
We study collective excitation modes of a fermionic gas of Li-6 atoms in the BEC-BCS crossover regime. While measurements of the axial compression mode in the cigar-shaped trap close to a Feshbach resonance confirm theoretical expectations, the radial compression mode shows surprising features. In the strongly interacting molecular BEC regime, we observe a negative frequency shift with increasing coupling strength. In the regime of a strongly interacting Fermi gas, an abrupt change in the collective excitation frequency occurs, which may be a signature for a transition from a superfluid to a collisionless phase.
引用
收藏
页码:203201 / 1
页数:4
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