title: High temperature ferromagnetism in GaAs-based heterostructures with Mn delta doping.
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.
authors.affiliation: Department of Electronic Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: A M
authors.initials: AM
authors.lastname: Nazmul
authors.forename: T
authors.initials: T
authors.lastname: Amemiya
authors.forename: Y
authors.initials: Y
authors.lastname: Shuto
authors.forename: S
authors.initials: S
authors.lastname: Sugahara
authors.forename: M
authors.initials: M
authors.lastname: Tanaka