Locally Reconfigurable Exchange Bias for Tunable Spintronics by Pulsed Current Injection

Unidirectional magnetic anisotropy induced by exchange bias (EB) between ferromagnetic and antiferromagnetic layers is of paramount importance in various spintronic devices. Traditional setting and optimization of EB involve cooling through the Néel temperature of the antiferromagnets under biasing field in vacuum furnace which takes hours of time and cannot realize localized control of EB. Herein, an alternative process to configure EB by injection of microsecond current impulse for locally heating of the heterostructure is reported. 180-degree exchange bias switching has been realized in both anisotropic magnetoresistance and giant magnetoresistance units, resulting in tunable magnetic field sensing functionalities. This mechanism for pinpoint control of EB provides more freedom for the design and optimization of various sensing and logic spintronics.