Mesoscopic spin transport between strongly interacting Fermi gases
Mesoscopic spin transport between strongly interacting Fermi gases
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强相互作用费米气体之间的介观自旋输运
DOI：
10.1103/physrevresearch.2.023152
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发表时间：
2020
影响因子：
4.2
通讯作者：
Uchino Shun
中科院分区：
文献类型：
--
作者：
Sekino Yuta;Tajima Hiroyuki;Uchino Shun
我们通过量子点接触研究了强相互作用费米气体的介观自旋电流。本文利用线性响应理论和多体矩阵近似计算了准粒子对电流的贡献，在左、右储层的自旋极化大小相同但符号相反的情况下，计算了准粒子对电流的贡献。对于一个小的自旋偏置区，由于赝隙的形成，超流体转变温度附近的电流被强烈抑制。另一方面，对于一个大的自旋偏置区，气体变得高度极化，电流受到费米极化子引起的少数态密度增强的影响。我们还讨论了在大动量下与吸引极化子相关的准粒子峰的展宽，这与增强有关。
We investigate a mesoscopic spin current for strongly interacting Fermi gases through a quantum point contact. Under the situation in which spin polarizations in the left and right reservoirs are the same in magnitude but opposite in sign, we calculate the contribution of quasiparticles to the current by means of the linear response theory and many-body-matrix approximation. For a small spin-bias regime, the current in the vicinity of the superfluid transition temperature is strongly suppressed due to the formation of pseudogaps. For a large spin-bias regime where the gases become highly polarized, on the other hand, the current is affected by the enhancement of a minority density of states due to Fermi polarons. We also discuss the broadening of a quasiparticle peak associated with an attractive polaron at a large momentum, which is relevant to the enhancement.