Temperature-dependent transport in a sixfold degenerate two-dimensional electron system on a H-Si(111) surface

Abstract

Low-field magnetotransport measurements on a high mobility (mu=110,000 cm^2/Vs) two-dimensional (2D) electron system on a H-terminated Si(111) surface reveal a sixfold valley degeneracy with a valley splitting <= 0.1 K. The zero-field resistivity rho_{xx} displays strong temperature dependence for 0.07 < T < 25 K as predicted for a system with high degeneracy and large mass. We present a method for using the low-field Hall coefficient to probe intervalley momentum transfer (valley drag). The relaxation rate is consistent with Fermi liquid theory, but a small residual drag as T->0 remains unexplained.

5 pages, 4 figures; revised and slightly shortened for publication;

References in corpus (4)

• Giant Fluctuations of Coulomb Drag in a Bilayer System
• Effective mass suppression in dilute, spin-polarized two-dimensional electron systems
• Strongly enhanced effective mass in dilute two-dimensional electron systems: System-independent origin
• Intervalley scattering and weak localization in Si-based two-dimensional structures