Effective Field Theory for Cold Atoms

TL;DR

This paper reviews the application of Effective Field Theory to cold atom systems, highlighting universal behaviors in few-body physics and recent advances in multi-particle and lower-dimensional systems.

Contribution

It provides a comprehensive overview of EFT methods for cold atoms, including recent extensions to four-body and N-boson systems in two dimensions.

Findings

Universal features in few-body systems with large scattering length

Necessity of three-body forces for renormalization in multi-particle systems

Extensions of EFT to four-body and two-dimensional N-boson droplets

Abstract

Effective Field Theory (EFT) provides a powerful framework that exploits a separation of scales in physical systems to perform systematically improvable, model-independent calculations. Particularly interesting are few-body systems with short-range interactions and large two-body scattering length. Such systems display remarkable universal features. In systems with more than two particles, a three-body force with limit cycle behavior is required for consistent renormalization already at leading order. We will review this EFT and some of its applications in the physics of cold atoms. Recent extensions of this approach to the four-body system and N-boson droplets in two spatial dimensions will also be discussed.