Conical intersections in an ultracold gas

TL;DR

This paper demonstrates that conical intersections are common in multi-atom dipole-dipole systems and explores their effects on excitation transport, with potential experimental realization using Rydberg-dressed alkali atoms.

Contribution

It reveals the generic presence of conical intersections in multi-atom dipolar systems and analyzes their impact on excitation dynamics in a ring-trapped trimer.

Findings

Conical intersections are common in systems with more than two dipolar atoms.

The CI influences adiabatic excitation transport through decoherence and geometric phase effects.

Experimental setup with Rydberg-dressed alkali atoms can probe many-body dynamics near CIs.

Abstract

We find that energy surfaces of more than two atoms or molecules interacting via dipole-dipole po- tentials generically possess conical intersections (CIs). Typically only few atoms participate strongly in such an intersection. For the fundamental case, a circular trimer, we show how the CI affects adiabatic excitation transport via electronic decoherence or geometric phase interference. These phe- nomena may be experimentally accessible if the trimer is realized by light alkali atoms in a ring trap, whose dipole-dipole interactions are induced by off-resonant dressing with Rydberg states. Such a setup promises a direct probe of the full many-body density dynamics near a conical intersection.