Electric field modulation of magnetoresistance in multiferroic heterostructures for ultralow power electronics

An energy-efficiency technique for electrically modulating magnetoresistance was demonstrated in multiferroic anisotropic magnetoresistance (AMR) and giant magnetoresistance (GMR) heterostructures. A giant electric field (E-field) induced magnetic anisotropy caused by a strong magnetoelectric coupling was utilized to control the orientation of magnetization and thus dynamically manipulate magnetoresistance in AMR and GMR devices. A multiband tunable AMR field sensor was designed and developed to dramatically enhance the measurement range by 15 times. In addition, two types of E-field determination of GMR in spin-valve structures are studied. The results indicate an energy efficiency approach to controlling magnetoresistance by E-field rather than magnetic field, which shows great potential for novel low power electronic and spintronic devices. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3597796]