Abstract
By measuring longitudinal resistance, we map the Landau-level spectra of double quantum wells as a function of both parallel () and perpendicular () magnetic fields. In this continuously tunable highly nonparabolic system, both the cyclotron mass and Fermi energy of the two Fermi surface orbits change in opposite directions with . The two corresponding ladders of Landau levels formed at finite thus exhibit multiple crossings. A third set of Landau levels, independent of , arises from magnetic breakdown of the Fermi surface. Semiclassical calculations show good agreement with the data.
DOI:https://doi.org/10.1103/PhysRevB.55.R13405
©1997 American Physical Society