The authors show that staggered asymmetric planar Hall resistance (PHR) loops observed in GaMnAs ferromagnetic semiconductor films with biaxial in-plane magnetic anisotropy result in four stable resistance states at zero magnetic field owing to the formation of a stable multidomain structure during magnetization reversal. The values of PHR can be systematically controlled by changing the direction and the scanning range of the applied magnetic field. The possibility of a quaternary memory device based on the observed four PHR states is demonstrated by obtaining consistent results in the writing process using appropriate sequences of magnetic field pulses.
Bibliographical noteFunding Information:
This research was supported by NSF Grant No. DMR06-03752, by Korea Research Foundation Grant No. KRF-2004-005-C00068, by the Seoul R&BD Program, and by the KOSEF through QSRC at Dongguk University.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)