Thomas J E, Kinast J, Turlapov A
Physics Department, Duke University, Durham, North Carolina 27708-0305, USA.
Phys Rev Lett. 2005 Sep 16;95(12):120402. doi: 10.1103/PhysRevLett.95.120402. Epub 2005 Sep 13.
Unitary Fermi gases, where the scattering length is large compared to the interparticle spacing, can have universal properties, which are independent of the details of the interparticle interactions when the range of the scattering potential is negligible. We prepare an optically trapped, unitary Fermi gas of 6Li, tuned just above the center of a broad Feshbach resonance. In agreement with the universal hypothesis, we observe that this strongly interacting many-body system obeys the virial theorem for an ideal gas over a wide range of temperatures. Based on this result, we suggest a simple volume thermometry method for unitary gases. We also show that the observed breathing mode frequency, which is close to the unitary hydrodynamic value over a wide range of temperature, is consistent with a universal hydrodynamic gas with nearly isentropic dynamics.
单一费米气体中，散射长度比粒子间间距大得多，当散射势的范围可忽略不计时，其可具有与粒子间相互作用细节无关的普适性质。我们制备了一个光学囚禁的6Li单一费米气体，将其调谐至刚好高于一个宽费什巴赫共振的中心。与普适假设一致，我们观察到这个强相互作用多体系统在很宽的温度范围内遵循理想气体的维里定理。基于这一结果，我们提出了一种针对单一气体的简单体积测温法。我们还表明，在很宽的温度范围内接近单一流体动力学值的观测到的呼吸模式频率，与具有近等熵动力学的普适流体动力学气体相符。
