Magnetic resonance of 2D electrons in a single quantum well of InP/GaInAs

The authors have measured , by magnetic resonance, for the first time the g-factor for electrons in the two-dimensional (2D) electron gas of a quantum well using the method of optical pumping. The value of mod g e mod =5.6+or-0.3 obtained for a single InP/GaInAs lattice-matched quantum well is approximately 70% greater than the accepted bulk value of mod g e mod =3.38 for GaInAs which implies that this value is too low or that, if exchange effects are negligible as expected for this low field measurement, the modification of the band structure in the 2D system results in an enhanced g-value.