Extracting the condensate density from projection experiments with Fermi gases.
Extracting the condensate density from projection experiments with Fermi gases.
复制标题
从费米气体投影实验中提取凝聚态密度。
DOI：
10.1103/physrevlett.95.010407
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发表时间：
2005
影响因子：
8.6
通讯作者：
G. Strinati
中科院分区：
文献类型：
--
作者：
A. Perali;P. Pieri;G. Strinati
一个有争议的问题，在物理学的BCS-BEC交叉与被困费米原子是确定的特征性质的超流相。最近，通过以快速（非绝热）方式从BCS到玻色-爱因斯坦凝聚（BEC）侧扫描系统，在交叉的BCS侧测量了凝聚分数，从而将初始多体状态“投影”到分子凝聚上。我们在这里分析这些投影实验的理论意义，通过确定适当的量子力学运营商与测量的数量，并将它们与发生在BCS-BEC交叉的多体相关性。计算在宽的温度和耦合范围内，包括配对波动的平均场。
A debated issue in the physics of the BCS-BEC crossover with trapped Fermi atoms is to identify characteristic properties of the superfluid phase. Recently, a condensate fraction was measured on the BCS side of the crossover by sweeping the system in a fast (nonadiabatic) way from the BCS to the Bose-Einstein condensation (BEC) sides, thus "projecting" the initial many-body state onto a molecular condensate. We analyze here the theoretical implications of these projection experiments, by identifying the appropriate quantum-mechanical operator associated with the measured quantities and relating them to the many-body correlations occurring in the BCS-BEC crossover. Calculations are presented over wide temperature and coupling ranges, by including pairing fluctuations on top of the mean field.