Interactions Between Rydberg-Dressed Atoms

TL;DR

This paper investigates how Rydberg-dressed atoms, with their tunable dipole moments, exhibit unique interaction behaviors that differ from classical dipolar interactions, potentially enabling new quantum phases.

Contribution

It provides a detailed calculation of Rydberg-dressed atom interactions, revealing R-dependent behaviors limited by blockade effects and differing from traditional dipolar interactions.

Findings

Interaction energies are limited by blockade effects.

Interactions can be R-independent up to a certain energy threshold.

Unique R-dependent interactions may lead to novel quantum phases.

Abstract

We examine interactions between atoms continuously and coherently driven between the ground state and a Rydberg state, producing "Rydberg-dressed atoms." Because of the large dipolar coupling between two Rydberg atoms, a small admixture of Rydberg character into a ground state can produce an atom with a dipole moment of a few Debye, the appropriate size to observe interesting dipolar physics effects in cold atom systems. We have calculated the interaction energies for atoms that interact via the dipole-dipole interaction and find that due to blockade effects, the R-dependent two-atom interaction terms are limited in size, and can be R-independent up until the dipolar energy is equal to the detuning. This produces R-dependent interactions different from the expected 1/R^3 dipolar form, which have no direct analogy in condensed matter physics, and could lead to new quantum phases in trapped Rydberg systems.