Exploring Universality of Few-Body Physics Based on Ultracold Atoms Near Feshbach Resonances

TL;DR

This paper reviews the concept of universality in few-body quantum systems near Feshbach resonances, emphasizing experimental techniques to explore these phenomena in ultracold atomic gases.

Contribution

It provides a comprehensive discussion on universality in ultracold atoms, including new experimental methods for studying few-body physics near Feshbach resonances.

Findings

Universal behavior characterized by two-body scattering length

Experimental strategies for controlling interactions in ultracold gases

Insights into Efimov physics and mean field corrections

Abstract

A universal characterization of interactions in few- and many-body quantum systems is often possible without detailed description of the interaction potential, and has become a defacto assumption for cold atom research. Universality in this context is defined as the validity to fully characterize the system in terms of two-body scattering length. We discuss universality in the following three contexts: closed-channel dominated Feshbach resonance, Efimov physics near Feshbach resonances, and corrections to the mean field energy of Bose-Einstein condensates with large scattering lengths. Novel experimental tools and strategies are discussed to study universality in ultracold atomic gases: dynamic control of interactions, run-away evaporative cooling in optical traps, and preparation of few-body systems in optical lattices.