Magnetic-field-induced hybridization of electron subbands in a coupled double quantum well
Dolgopolov V.T., Tsydynzhapov G.E., Shashkin A.A., Deviatov E.V., Hastreiter F., Hartung M., Wixforth A, Campman K.L., Gossard A.C.
PACS: 72.20.My, 73.40.Kp
We employ a magneto capacitance technique to study the spectrum of the soft two-subband (or double-layer) electron system in a parabolic quantum well with a narrow tunnel barrier in the centre. In this system unbalanced by gate depletion, at temperatures Τ > 30 mK we observe two sets of quantum oscillations: one originates from the upper electron subband in the closer-to-the-gate part of the well and the other indicates the existence of common gaps in the spectrum at integer fillings. For the lowest filling factors ν — 1 and ν — 2, both the common gap presence down to the point of oneto two-subband transition and their non-trivial magnetic field dependences point to magnetic-field-induced hybridization of electron subbands.