Rubidium Rydberg macrodimers

TL;DR

This paper investigates long-range interactions between high-n Rydberg rubidium atoms, calculating potential energy surfaces that reveal deep wells capable of supporting extended bound states called macrodimers, and proposes methods to form and analyze them.

Contribution

It provides detailed calculations of potential energy surfaces for Rydberg rubidium atom pairs, revealing deep wells and scaling relations, and introduces a scheme for their formation and study.

Findings

Potential wells of ~GHz depth support macrodimers.

Scaling relations for well depth and equilibrium separation.

Proposed photoassociation scheme to create and probe macrodimers.

Abstract

We explore long-range interactions between two atoms excited into high principal quantum number n Rydberg states, and present calculated potential energy surfaces (PES) for various symmetries of doubly excited ns and np rubidium atoms. We show that the PES for these symmetries exhibit deep (~GHz) potential wells, which can support very extended (~micrometers) bound vibrational states (macrodimers). We present n-scaling relations for both the depth De of the wells and the equilibrium separations Re of these macrodimers, and explore their response to small electric fields and stability with respect to predissociation. Finally, we present a scheme to form and study these macrodimers via photoassociation, and show how one can probe the various \ell-character of the potential wells.