LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, 50019 Sesto Fiorentino, Italy.
Istituto Nazionale di Ottica del Consiglio Nazionale delle Ricerche (INO-CNR), 50019 Sesto Fiorentino, Italy.
Phys Rev Lett. 2018 Dec 21;121(25):253602. doi: 10.1103/PhysRevLett.121.253602.
We exploit a time-resolved pump-probe spectroscopic technique to study the out-of-equilibrium dynamics of an ultracold two-component Fermi gas, selectively quenched to strong repulsion along the upper branch of a broad Feshbach resonance. For critical interactions, we find the rapid growth of short-range anticorrelations between repulsive fermions to initially overcome concurrent pairing processes. At longer evolution times, these two competing mechanisms appear to macroscopically coexist in a short-range correlated state of fermions and pairs, unforeseen thus far. Our work provides fundamental insights into the fate of a repulsive Fermi gas, and offers new perspectives towards the exploration of complex dynamical regimes of fermionic matter.
我们利用时间分辨泵浦探测光谱技术研究了处于非平衡态的超冷双组分费米气体的动力学，该气体沿宽的费什巴赫共振的上分支被选择性地猝灭到强排斥。对于临界相互作用，我们发现短程反相关迅速增长，从而最初克服了同时发生的配对过程。在更长的演化时间内，这两种竞争机制似乎在费米子和对的短程相关态中共存，这是迄今为止未曾预料到的。我们的工作为研究排斥费米气体的命运提供了基本的见解，并为探索费米物质的复杂动力学状态提供了新的视角。
