title: Dependence of spin susceptibility of a two-dimensional electron system on the valley degree of freedom.
abstract: We report measurements of the spin susceptibility, chi proportional, variant g(v)g*m*, in an AlAs two-dimensional electron system where, via the application of in-plane stress, we transfer electrons from one ellipsoidal conduction-band valley to another (g(v) is the valley degeneracy, and m* and g* are the electron effective mass and g factor). At a given density, when the two valleys are equally populated (g(v)=2), the measured g*m* is smaller than when only one valley is occupied (g(v)=1). This observation counters the common assumption that a two-valley two-dimensional system is effectively more dilute than a single-valley system because of its smaller Fermi energy.
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Y P
authors.initials: YP
authors.lastname: Shkolnikov
authors.forename: K
authors.initials: K
authors.lastname: Vakili
authors.forename: E P
authors.initials: EP
authors.lastname: De Poortere
authors.forename: M
authors.initials: M
authors.lastname: Shayegan