title: Atomic pseudospin resonance.
abstract: A new type of resonance is discovered in Rydberg atoms placed in a constant magnetic field -->B and a transient electric field that rotates at the constant frequency -->omega in a plane perpendicular to -->B. The dynamics is explained in terms of two pseudoparticles with spin 1 / 2 in two generalized magnetic fields. The resonance frequency is predicted and found at -->omega = (e/2m)-->B, where -e/m is the electron's charge-to-(reduced)mass ratio. We discuss the applicability of the resonance to accurate magnetic field measurements and the prospects for determining e/m with improved precision.
authors.affiliation: Institute of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: D
authors.initials: D
authors.lastname: Fregenal
authors.forename: T
authors.initials: T
authors.lastname: Ehrenreich
authors.forename: B
authors.initials: B
authors.lastname: Henningsen
authors.forename: E
authors.initials: E
authors.lastname: Horsdal-Pedersen
authors.forename: L
authors.initials: L
authors.lastname: Nyvang
authors.forename: V N
authors.initials: VN
authors.lastname: Ostrovsky