Spin Collective Modes of Two-Species Fermi Liquids: Helium-3 and Atomic Gases near the Feshbach Resonance

TL;DR

This paper investigates the spin collective modes in two-species Fermi liquids, focusing on atomic gases near Feshbach resonances and comparing them with Helium-3, revealing tunable properties influenced by diverging scattering lengths.

Contribution

It provides a theoretical analysis of how Feshbach resonances affect spin modes in Fermi liquids, highlighting differences from traditional Helium-3 systems.

Findings

Spin modes are affected by diverging s-wave scattering length near Feshbach resonance.

The gap and spin stiffness are tunable via the Feshbach resonance.

Atomic gas modes differ from those in conventional Helium-3 systems.

Abstract

We present theoretical findings on the spin collective modes of a two-species Fermi liquid, prepared alternatively in a polarized equilibrium or a polarized non-equilibrium state. We explore the effects on these modes of a diverging s-wave scattering length, as occurs near a Feshbach resonance in a Fermionic atomic gas. We compare these atomic gas modes with those of the conventional Helium-3 system, and we find that they differ from the conventional systems, and that the gap and spin stiffness are tunable via the Feshbach resonance.