Probing interactions between Rydberg atoms with large electric dipole moments in amplitude modulated electric fields

摘要

Dipole-dipole interactions between helium atoms in Rydberg-Stark states withprincipal quantum number $n=53$ and approximately linear Stark energy shifts,resulting from induced electric dipole moments of approximately 7900 D, havebeen investigated experimentally. The experiments were performed in pulsedsupersonic metastable helium beams, with particle number densities of up to$\sim10^9$ cm$^{-3}$. In the presence of amplitude-modulated, radio-frequencyelectric fields, changes in the spectral intensity distributions associatedwith the transitions to these states that are attributed to dipole-dipoleinteractions within the ensembles of excited atoms have been observed. Theexperimental results are in excellent agreement with calculations of theRydberg energy level structure carried out using Floquet methods, andexcitations shared by up to 4 atoms. The use of these Rydberg-Stark states assensors for non-resonant broadband radio-frequency electrical noise is alsodiscussed.