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Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
Published on: December 3, 2013
High temperature ferromagnetism in GaAs-based heterostructures with Mn delta doping
A M Nazmul1, T Amemiya, Y Shuto
1Department of Electronic Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Abstract:
We show that suitably designed magnetic semiconductor heterostructures consisting of Mn delta (delta)-doped GaAs and p-type AlGaAs layers, in which the locally high concentration of magnetic moments of Mn atoms are controllably overlapped with the two-dimensional hole gas wave function, realized remarkably high ferromagnetic transition temperatures (T(C)). A significant reduction of compensative Mn interstitials by varying the growth sequence of the structures followed by low-temperature annealing led to high T(C) up to 250 K. The heterostructure with high T(C) exhibited peculiar anomalous Hall effect behavior, whose sign depends on temperature.
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