Berlin 2018 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 42: Transport
HL 42.2: Talk
Thursday, March 15, 2018, 15:15–15:30, EW 015
Interlayer Tunneling between Imbalanced Double Quantum Wells in the Quantum Hall Regime — •Gunnar Schneider1, Rolf J. Haug1, and Werner Dietsche2 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover, Germany — 2Max Planck Institut for Solid State Reasearch, 70569 Stuttgart, Germany
Bilayer phenomena such as 2D-2D Tunneling [1] or excitonic Bose-Einstein condensates (BEC) [2] are observable within double quantum wells in the quantum Hall regime. The BEC was found to arise at balanced layer densities with the filling factor combination of 1/2 and 1/2. In our work we are focusing on imbalanced layers, allowing not only the investigation of the filling factor combination 1/3 and 2/3 but also the systems behavior at various combinations of greater filling factors. All measurements were performed on a MBE grown GaAs double quantum well separated by a 10 nm AlAs/GaAs barrier. Gates allow tuning the charge carrier densities between 1E10 and 4E10. The interlayer tunneling for imbalanced charge carrier densities is measured and compared to balanced conditions existing in the samples leads. Measurements were performed at magnetic fields up to three Tesla and for varying density ratios. We were able to map the emergence of the excitonic condensate in the filling factor space. Furthermore regions of conductance and insulation were found at combination of higher filling factors referable to each layers individual Quanten Hall state.
[1]N. Turner et al., Phys. Rev. B 54(15), (1996).
[2]J.P. Eisenstein and A.H. MacDonald, Nature 432, 691-694 (2004)