title: Spin-independent origin of the strongly enhanced effective mass in a dilute 2D electron system.
abstract: We accurately measure the effective mass in a dilute two-dimensional electron system in silicon by analyzing the temperature dependence of the Shubnikov-de Haas oscillations in the low-temperature limit. A sharp increase of the effective mass with decreasing electron density is observed. We find that the enhanced effective mass is independent of the degree of spin polarization, which points to a spin-independent origin of the mass enhancement and is in contradiction with existing theories.
authors.affiliation: Physics Department, Northeastern University, Boston, Massachusetts 02115, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Shashkin
authors.forename: Maryam
authors.initials: M
authors.lastname: Rahimi
authors.forename: S
authors.initials: S
authors.lastname: Anissimova
authors.forename: S V
authors.initials: SV
authors.lastname: Kravchenko
authors.forename: V T
authors.initials: VT
authors.lastname: Dolgopolov
authors.forename: T M
authors.initials: TM
authors.lastname: Klapwijk