Kinast J, Turlapov A, Thomas J E
Department of Physics, Duke University, Durham, North Carolina 27708, USA.
Phys Rev Lett. 2005 May 6;94(17):170404. doi: 10.1103/PhysRevLett.94.170404.
We measure the temperature dependence of the radial breathing mode in an optically trapped, unitary Fermi gas of 6Li, just above the center of a broad Feshbach resonance. The damping rate reveals a clear change in behavior which we interpret as arising from a superfluid transition. We suggest pair breaking as a mechanism for an increase in the damping rate which occurs at temperatures well above the transition. In contrast to the damping, the frequency varies smoothly and remains close to the unitary hydrodynamic value. At low temperature T, the damping depends on the atom number only through the reduced temperature, and extrapolates to 0 at T = 0.
我们测量了处于光学捕获状态的6Li单一费米气体中径向呼吸模式的温度依赖性，该气体刚好位于一个宽费什巴赫共振中心上方。阻尼率显示出行为上的明显变化，我们将其解释为超流转变所致。我们提出配对破裂是温度远高于转变温度时阻尼率增加的一种机制。与阻尼不同，频率变化平滑且接近单一流体动力学值。在低温T下，阻尼仅通过约化温度依赖于原子数，并在T = 0时外推至0。
