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arXiv · cond-mat/9208014

Electron focusing, mode spectroscopy and mass enhancement in small GaAs/AlGaAs rings

J Liu·K Ismail·KY Lee·JM Hong·S Washburn
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Abstract

A new electron focusing effect has been discovered in small single and coupled GaAs/AlGaAs rings. The focusing in the single ring is attributed solely to internal orbits. The focusing effect allows the ring to be used as a small mass spectrometer. The focusing causes peaks in the magnetoresistance at low fields, and the peak positions were used to study the dispersion relation of the one-dimensional magnetoelectric subbands. The electron effective mass increases with the applied magnetic field by a factor of $50$, at a magnetic field of $0.5T$. This is the first time this increase has been measured directly. General agreement obtains between the experiment and the subband calculations for straight channels.

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J Liu, K Ismail, KY Lee, JM Hong, S Washburn. 1992-08-20. Electron focusing, mode spectroscopy and mass enhancement in small GaAs/AlGaAs rings. https://doi.org/10.1103/physrevb.47.13039

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