Luo L, Clancy B, Joseph J, Kinast J, Thomas J E
Department of Physics, Duke University, Durham, NC 27708, USA.
Phys Rev Lett. 2007 Feb 23;98(8):080402. doi: 10.1103/PhysRevLett.98.080402. Epub 2007 Feb 21.
We report a model-independent measurement of the entropy, energy, and critical temperature of a degenerate, strongly interacting Fermi gas of atoms. The total energy is determined from the mean square cloud size in the strongly interacting regime, where the gas exhibits universal behavior. The entropy is measured by sweeping a bias magnetic field to adiabatically tune the gas from the strongly interacting regime to a weakly interacting regime, where the entropy is known from the cloud size after the sweep. The dependence of the entropy on the total energy quantitatively tests predictions of the finite-temperature thermodynamics.
我们报告了一种对简并、强相互作用的原子费米气体的熵、能量和临界温度进行与模型无关的测量。总能量由强相互作用区域中的均方云团大小确定，在该区域气体呈现出普适行为。通过扫描偏置磁场将气体从强相互作用区域绝热调节到弱相互作用区域来测量熵，在扫描后，弱相互作用区域的熵可由云团大小得知。熵对总能量的依赖性定量地检验了有限温度热力学的预测。
