title: Giant collective spin-orbit field in a quantum well: fine structure of spin plasmons.
abstract: We employ inelastic light scattering with magnetic fields to study intersubband spin plasmons in a quantum well. We demonstrate the existence of a giant collective spin-orbit (SO) field that splits the spin-plasmon spectrum into a triplet. The effect is remarkable as each individual electron would be expected to precess in its own momentum-dependent SO field, leading to D'yakonov-Perel' dephasing. Instead, many-body effects lead to a striking organization of the SO fields at the collective level. The macroscopic spin moment is quantized by a uniform collective SO field, five times higher than the individual SO field. We provide a momentum-space cartography of this field.
authors.affiliation: Institut des Nanosciences de Paris, CNRS/Université Paris VI, Paris 75005, France. florent.baboux@insp.upmc.fr
authors.forename: F
authors.initials: F
authors.lastname: Baboux
authors.forename: F
authors.initials: F
authors.lastname: Perez
authors.forename: C A
authors.initials: CA
authors.lastname: Ullrich
authors.forename: I
authors.initials: I
authors.lastname: D'Amico
authors.forename: J
authors.initials: J
authors.lastname: Gómez
authors.forename: M
authors.initials: M
authors.lastname: Bernard