Shallow Trimers of Two Identical Fermions and One Particle in Resonant Regimes

TL;DR

This paper investigates the formation of shallow three-particle bound states involving two identical fermions and a third particle near s-wave resonance, revealing new trimers induced by p-wave interactions.

Contribution

It demonstrates that p-wave fermion-fermion interactions can produce additional shallow trimers, including Borromean states, expanding understanding of three-body systems near resonances.

Findings

Identification of p-wave induced trimers in fermionic systems.

Existence of Borromean trimers without dimers at certain mass ratios.

A universal spectrum description based on low-energy interaction parameters.

Abstract

We consider two identical fermions interacting in the p-wave channel. Each fermion also interacts with another particle in the vicinity of an s-wave resonance. We find that in addition to the Kartavtsev-Malykh universal trimer states resulting from the s-wave particle-fermion interaction, the fermion-fermion p-wave interaction induces one or two shallow trimers in a large domain of the control parameters, including a borromean regime where the ground-state trimer exists in the absence of dimers at any mass ratio between the fermions and the particle. A generic picture of the trimer spectrum emerges from this work in terms of the low-energy parameters of the interactions.