title: Many-body dipole-dipole interactions between excited Rb atoms probed by wave packets and parametric four-wave mixing.
abstract: Dipole-dipole interactions between excited Rb atoms at long range (approximately 300a0-2150a0) have been observed with molecular wave packets and a coherent nonlinear optical process. Fourier analysis of the parametric four-wave mixing (PFWM) signal wave intensity produced in femtosecond pump-probe experiments demonstrates the appearance of sidebands associated with the Rb 7s-5d(5/2) quantum beating frequency of approximately 18.3 THz. Calculations show that the observed sideband splittings and Fourier domain profiles result from multiple atom, dipole-dipole interactions, and ensembles comprising five or fewer Rb (7s, 6p) atoms account for virtually all of the data.
authors.affiliation: Laboratory for Optical Physics and Engineering, Department of Electrical and Computer Engineering, University of Illinois, Urbana, IL 61801, USA.
authors.forename: F
authors.initials: F
authors.lastname: Shen
authors.forename: J
authors.initials: J
authors.lastname: Gao
authors.forename: A A
authors.initials: AA
authors.lastname: Senin
authors.forename: C J
authors.initials: CJ
authors.lastname: Zhu
authors.forename: J R
authors.initials: JR
authors.lastname: Allen
authors.forename: Z H
authors.initials: ZH
authors.lastname: Lu
authors.forename: Y
authors.initials: Y
authors.lastname: Xiao
authors.forename: J G
authors.initials: JG
authors.lastname: Eden