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HL: Fachverband Halbleiterphysik
HL 80: Quantum transport and quantum Hall effects
HL 80.3: Talk
Friday, March 20, 2020, 10:00–10:15, POT 51
Magnetotunnelspectroscopy of Double-Quantum-Wells in GaAs/AlGaAs Heterostructures — •Maximillian Mischke1, Gunnar Schneider1, Werner Dietsche2, and Rolf J. Haug1 — 1Leibniz Universität Hannover, Institut für Festkörperphysik, Germany — 2Max-Planck Institut für Festkörperforschung, Stuttgart, Germany
In order to investigate the influence of a parallel magnetic field on bilayer phenomena, we performed magnetotunnel measurements on GaAs/AlGaAs double quantum wells. Therefore the tunneling current between the two quantum wells was measured dependent on applied bias voltage, electron densities in the individual wells and a magnetic field oriented parallel to the 2D layers. We observe a systematic dependence of the tunneling resonance on the energetic difference of the two wells due to imbalanced densities. The applied bias compensates the mismatch. The parallel magnetic field introduces an additional term to the wave vector of the electrons, leading to a shift of the Fermi circles of the two quantum wells against each other [1]. This shift has an influence on the tunneling resonance since 2D-2D-tunneling requires not only energy conservation but also conservation of momentum [2]. Our measurements reveal an energetic splitting of the tunneling conductance with magnetic field. This splitting starts at a certain magnetic field depending on the density ratio. We expect many-particle-effects to influence this offset field.
[1] G.S. Boebinger et al, Phys. Rev. B 43, 12673 (1991)
[2] J.P. Eisenstein et al, Appl. Phys. Lett. 58, 1497 (1991)