title: Direct measurement of the spin gaps in a gated GaAs two-dimensional electron gas.
abstract: We have performed magnetotransport measurements on gated GaAs two-dimensional electron gases in which electrons are confined in a layer of the nanoscale. From the slopes of a pair of spin-split Landau levels (LLs) in the energy-magnetic field plane, we can perform direct measurements of the spin gap for different LLs. The measured g-factor g is greatly enhanced over its bulk value in GaAs (0.44) due to electron-electron (e-e) interactions. Our results suggest that both the spin gap and g determined from conventional activation energy studies can be very different from those obtained by direct measurements.
authors.affiliation: Department of Physics, National Taiwan University, Taipei 106, Taiwan. ctliang@phys.ntu.edu.tw.
authors.forename: Tsai-Yu
authors.initials: TY
authors.lastname: Huang
authors.forename: Chi-Te
authors.initials: CT
authors.lastname: Liang
authors.forename: Yang Fang
authors.initials: YF
authors.lastname: Chen
authors.forename: Michelle Y
authors.initials: MY
authors.lastname: Simmons
authors.forename: Gil-Ho
authors.initials: GH
authors.lastname: Kim
authors.forename: David A
authors.initials: DA
authors.lastname: Ritchie