Direct measurement of the spin gaps in a gated GaAs two-dimensional electron gas
1 Department of Physics, National Taiwan University, Taipei 106, Taiwan
2 School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia
3 School of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 440-746, South Korea
4 Cavendish Laboratory, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK
Nanoscale Research Letters 2013, 8:138 doi:10.1186/1556-276X-8-138Published: 25 March 2013
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.