Is. Millard et al., PROBING THE FERMI SURFACES OF COUPLED DOUBLE-QUANTUM WELLS IN THE PRESENCE OF AN INPLANE MAGNETIC-FIELD, Journal of physics. Condensed matter, 9(5), 1997, pp. 1079-1094
The anticrossing of the dispersion relations of two two-dimensional el
ectron gases (2DEGs) in an in-plane magnetic field results in distorte
d Fermi surfaces, leading to density of states and effective mass chan
ges. We have used two different techniques to probe such changes with
both the in-plane field and carrier density being systematically alter
ed. The first technique uses a fixed perpendicular field to form Landa
u levels. By following the evolution of these Landau levels with in-pl
ane field, carrier density and temperature, we are able to determine c
hanges in the subband populations and effective masses. The second tec
hnique uses a third conducting layer as a detector of chemical potenti
al changes in the coupled electron gases. This method also allows the
determination of effective mass changes in an in-plane field. Calculat
ions of the dispersion curves have been made, illustrating the effect
of the parallel held upon subband occupancy and effective mass. These
calculations are compared with the experimental data from both methods
and are found to be in good agreement.