$P$-wave Efimov physics implications at unitarity

TL;DR

This paper explores how $p$-wave interactions influence universal behaviors in fermionic trimers near unitarity, revealing a remnant of Efimov physics that affects scattering laws and matches experimental data.

Contribution

It demonstrates a new universality in fermionic trimers at $p$-wave unitarity, extending Efimov physics concepts beyond the traditional $s$-wave case using a Lennard-Jones potential model.

Findings

Identification of a $L^{ ext{"}1^{-}"}$ universality class.

Modified threshold and scaling laws at $p$-wave unitarity.

Application to lithium atom experiments explaining recombination rates.

Abstract

Equal mass fermionic trimers with two different spin components near the unitary limit are shown to possess a universal van der Waals bound or resonance state near $s$-wave unitarity, when $p$-wave interactions are included between the particles with equal spin. Our treatment uses a single-channel Lennard-Jones interaction with long range two-body van der Waals potentials. While it is well-known that there is no true Efimov effect that would produce an infinite number of bound states in the unitary limit, we demonstrate that another type of universality emerges for the symmetry $L^{\Pi}=1^{-}$. The universality is a remnant of Efimov physics that exists in this system at $p$-wave unitarity, and it leads to modified threshold and scaling laws in that limit. Application of our model to the system of three lithium atoms studied experimentally by Du, Zhang, and Thomas [Phys. Rev. Lett. {\bf 102}, 250402 (2009)] yields a detailed interpretation of their measured three-body recombination loss rates.