Using giant magneto resistance stripes to efficiently generate direct voltage signals from alternating current excitations

作者：Kleinlein J; Ocker B; Schmidt G^*

来源：Applied Physics Letters, 2014, 104(15): 153507.

DOI：10.1063/1.4871383

We have developed all metal spintronic devices which convert an alternating current (AC) in-plane current into a direct current (DC) voltage without using external magnetic fields. The devices are based on the modulation of the magnetization of the free magnetic layer in an exchange biased giant magneto resistance nanowire by the current-induced Oersted field. They can be operated at frequencies extending into the GHz range, and the resistance is easily tunable by changing the wire length. The devices can be operated on-or off-resonance. Even off-resonance we demonstrate an efficiency of 0.7 mV DC-output voltage per 1 mW input power. At ferromagnetic resonance, the efficiency is increased and can be as high as 1: 8 V/W in zero magnetic field. The efficiency of the devices can also be tuned by applying external magnetic fields. The device performance is dominated by the interplay of the Oersted field and the shape anisotropy of the free layer, and for narrow wires the output signal becomes smaller while the possible range of external magnetic fields is extended. The nanowires are easily scalable allowing for higher output voltages or fine tuning of the resistance to match the impedance for RF applications.

• 出版日期2014-4-14