title: Fast optimal frictionless atom cooling in harmonic traps: shortcut to adiabaticity.
abstract: A method is proposed to cool down atoms in a harmonic trap without phase-space compression as in a perfectly slow adiabatic expansion, i.e., keeping the same populations of instantaneous levels in the initial and final traps, but in a much shorter time. This may require that the harmonic trap become transiently an expulsive parabolic potential. The cooling times achieved are shorter than those obtained using optimal-control bang-bang methods and real frequencies.
authors.affiliation: Departamento de Química-Física, UPV-EHU, Apartado 644, 48080 Bilbao, Spain.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Ruschhaupt
authors.forename: S
authors.initials: S
authors.lastname: Schmidt
authors.forename: A
authors.initials: A
authors.lastname: del Campo
authors.forename: D
authors.initials: D
authors.lastname: Guéry-Odelin
authors.forename: J G
authors.initials: JG
authors.lastname: Muga