Dynamics of spin-polarized impurity in ultracold Fermi gas

We show that the motion of spin-polarized impurity (ferron) in ultracold atomic gas is characterized by a certain critical velocity which can be traced back to the amount of spin imbalance inside the impurity. We have calculated the effective mass of ferron in two dimensions. We show that the effective mass scales with the surface of the ferron. We discuss the impact of these findings; in particular, we demonstrate that ferrons become unstable in the vicinity of a vortex.

Automated summary

The motion of spin-polarized impurity in ultracold atomic gas is determined by a critical velocity, which correlates with the spin imbalance inside the impurity. The effective mass of the impurity in two dimensions is calculated, showing a scaling relationship with the impurity's surface area. The instability of impurities near a vortex is demonstrated as a significant impact of these findings.