The effective [Formula presented] factor [Formula presented] of a dilute interacting two-dimensional electron system is expected to increase with respect to its bare value as the density is lowered, and to eventually diverge as the system makes a transition to a ferromagnetic state. We report here measurements of [Formula presented] in dilute (density 0.8 to [Formula presented]), high-mobility GaAs two-dimensional electrons from their spin polarization in a parallel magnetic field. The data reveal a surprising trend. While [Formula presented] is indeed significantly enhanced with respect to the band [Formula presented] factor of GaAs, the enhancement factor decreases from about 6 to 3 as the density is reduced.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)