Resonant enhancement of ultracold photoassociation rate by electric field induced anisotropic interaction

TL;DR

This paper demonstrates how a static electric field can significantly enhance ultracold photoassociation rates of heteronuclear atoms by inducing anisotropic interactions and resonances, enabling control over molecular formation processes.

Contribution

It introduces the concept of electric field induced anisotropic resonances that dramatically increase photoassociation rates and enable excitation of higher rotational levels in ultracold molecules.

Findings

Photoassociation rate is enhanced by several orders of magnitude near electric field resonances.

Electric field induces anisotropic scattering resonances at specific field strengths.

Higher rotational levels can be excited due to tunable resonances.

Abstract

We study the effects of a static electric field on the photoassociation of a heteronuclear atom-pair into a polar molecule. The interaction of permanent dipole moment with a static electric field largely affects the ground state continuum wave function of the atom-pair at short separations where photoassociation transitions occur according to Franck-Condon principle. Electric field induced anisotropic interaction between two heteronuclear ground state atoms leads to scattering resonances at some specific electric fields. Near such resonances the amplitude of scattering wave function at short separation increases by several orders of magnitude. As a result, photoaasociation rate is enhanced by several orders of magnitude near the resonances. We discuss in detail electric field modified atom-atom scattering properties and resonances. We calculate photoassociation rate that shows giant enhancement due to electric field tunable anisotropic resonances. We present selected results among which particularly important are the excitations of higher rotational levels in ultracold photoassociation due to electric field tunable resonances.