title: Spin-independent effective mass in a valley-degenerate electron system.
abstract: In a generic spin-polarized Fermi liquid, the masses of spin-up and spin-down electrons are expected to be different and to depend on the degree of polarization. This expectation is not confirmed by the experiments on two-dimensional heterostructures. We consider a model of an N-fold degenerate electron gas. It is shown that in the large- limit, the mass is enhanced via a polaronic mechanism of emission or absorption of virtual plasmons. As plasmons are classical collective excitations, the resulting mass does not depend on , and thus on polarization, to the leading order in 1/N. We evaluate the 1/N corrections and show that they are small even for N = 2.
authors.affiliation: Department of Physics, University of Florida, P.O. Box 118440, Gainesville, Florida 32611-8440, USA.
authors.forename: Suhas
authors.initials: S
authors.lastname: Gangadharaiah
authors.forename: Dmitrii L
authors.initials: DL
authors.lastname: Maslov