Polaron-to-molecule transition in a strongly imbalanced Fermi gas
Polaron-to-molecule transition in a strongly imbalanced Fermi gas
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DOI：
10.1103/physreva.80.053605
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发表时间：
2009-08
影响因子：
2.9
通讯作者：
M. Punk;P. Dumitrescu;W. Zwerger
中科院分区：
文献类型：
--
作者：
M. Punk;P. Dumitrescu;W. Zwerger
单个自旋向下的费米子与一堆自旋向上的费米子发生吸引的零范围相互作用，形成一个极极性准粒子。相关的准部分粒子重量在吸引相互作用的临界强度之后消失，在那里形成了多体束缚态。从分子极限的变分波函数，我们确定了极化子到分子跃迁的临界值。该值与Prokof 'ev和Svist unov的蒙特卡罗图解结果很好地一致，并且与Schirotzek等人最近对准粒子质量的rf光谱测量结果一致。此外，我们利用Tan的绝热定理计算了强不平衡气体的接触系数，并讨论了极化子到分子跃迁对有限不平衡吸引费米气体相图的影响。
A single down spin Fermion with an attractive, zero range interaction with a Fermi sea of up-spin Fermions forms a polaronic quasiparticle. The associated quasipart icle weight vanishes beyond a critical strength of the attractive interaction, where a many-body bound state is formed. From a variational wavefunction in the molecular limit, we determine the critical value for the polaron t o molecule transition. The value agrees well with the diagrammatic Monte Carlo results of Prokof’ev and Svist unov and is consistent with recent rf-spectroscopy measurements of the quasiparticle weight by Schirotzek et. al. In addition, we calculate the contact coefficient of the strongly imbalanced gas, using the adiabatic theorem of Tan and discuss the implications of the polaron to molecule transition for the phase diagram of the attractive Fermi gas at finite imbalance.