Spin gap in the 2D electron system of GaAs/AlGaAs single heterojunctions in weak magnetic fields

Research paper by V. S. Khrapai, A. A. Shashkin, E. L. Shangina, V. Pellegrini, F. Beltram, G. Biasiol, L. Sorba

Indexed on: 13 Jul '05Published on: 13 Jul '05Published in: Physics - Strongly Correlated Electrons


We study the interaction-enhanced spin gaps in the two-dimensional electron gas confined in GaAs/AlGaAs single heterojunctions subjected to weak magnetic fields. The values are obtained from the chemical potential jumps measured by magnetocapacitance. The gap increase with parallel magnetic field indicates that the lowest-lying charged excitations are accompanied with a single spin flip at the odd-integer filling factor nu=1 and nu=3, in disagreement with the concept of skyrmions.