We employ magnetocapacitance and far-infrared spectroscopy techniques to study the spectrum of the double-layer electron system in a parabolic quantum well with a narrow tunnel barrier in the centre. For gate-bias-controlled asymmetric electron density distributions in this soft two-subband system we observe both individual subband gaps and double layer gaps at integer filling factor ν. The bilayer gaps are shown to be either trivial common for two subbands or caused by hybridization of electron subbands in magnetic field. We describe the observed hybrid gaps at ν=1 and ν=2 within a simple model for the modified bilayer spectrum.
@article{arxiv.cond-mat/9806203,
title = {Hybridization of electron subbands in a double quantum well at quantizing magnetic field},
author = {V. T. Dolgopolov and A. A. Shashkin and E. V. Deviatov and F. Hastreiter and M. Hartung and A. Wixforth and K. L. Campman and A. C. Gossard},
journal= {arXiv preprint arXiv:cond-mat/9806203},
year = {2009}
}
Comments
REVTeX, 24 pages, 9 figures included. Submitted to Phys. Rev. B