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arXiv · 1209.5226

Impact of current paths on measurement of tunneling magnetoresistance and spin torque critical current densities in GaMnAs-based magnetic tunnel junctions

Aymen Ben Hamida·Florian Bergmann·Klaus Pierz·Hans Werner Schumacher
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Abstract

GaMnAs-based magnetic tunnel junction (MTJ) devices are characterized by in-plane and perpendicular-toplane magnetotransport at low temperatures. Perpendicular-to-plane transport reveals the typical tunneling magnetotransport (TMR) signal. Interestingly, a similar TMR signature is observed in the in-plane transport signal. Here, low-ohmic shunting of the MTJ by the top contact results in significant perpendicular-to-plane current paths. This effect allows the determination of TMR ratios of MTJs based on a simplified in-plane measurement. However, the same effect can lead to an inaccurate determination of resistance area products and spin torque critical current densities from perpendicular-to-plane magnetotransport experiments on MTJ pillar structures.

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Aymen Ben Hamida, Florian Bergmann, Klaus Pierz, Hans Werner Schumacher. 2012-09-24. Impact of current paths on measurement of tunneling magnetoresistance and spin torque critical current densities in GaMnAs-based magnetic tunnel junctions. https://doi.org/10.1063/1.4793086

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