BCS-BEC crossover in a quasi-two-dimensional Fermi gas
BCS-BEC crossover in a quasi-two-dimensional Fermi gas
复制标题
DOI：
10.1103/physreva.88.023612
复制
发表时间：
2013-01
影响因子：
2.9
通讯作者：
A. Fischer;M. Parish
中科院分区：
文献类型：
--
作者：
A. Fischer;M. Parish
本文研究了在横向上被简谐势束缚在准二维几何中的两组分费米子原子气体。我们构建了一个平均场理论的BCS-BEC交叉在零温度下，使我们能够外推到无限数量的横向谐振子水平。在极端的BEC限制，限制长度超过二聚体的大小，我们恢复3D二聚体局限于2D弱排斥相互作用。然而，即使当相互作用很弱，费米能量小于限制频率，我们发现，更高的横向水平可以大大修改费米子配对。我们认为最近的准二维费米气体配对实验[Y. Zhang等人，物理修订信函108，235302（2012）]已经观察到更高横向能级的影响。
We consider a two-component gas of fermionic atoms confined to a quasi-two-dimensional (quasi-2D) geometry by a harmonic trapping potential in the transverse direction. We construct a mean field theory of the BCS-BEC crossover at zero temperature that allows us to extrapolate to an infinite number of transverse harmonic oscillator levels. In the extreme BEC limit, where the confinement length exceeds the dimer size, we recover 3D dimers confined to 2D with weak repulsive interactions. However, even when the interactions are weak and the Fermi energy is less than the confinement frequency, we find that the higher transverse levels can substantially modify fermion pairing. We argue that recent experiments on pairing in quasi-2D Fermi gases [Y. Zhang et al., Phys. Rev. Lett. 108, 235302 (2012)] have already observed the effects of higher transverse levels.