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arXiv · 1407.6313

Anomalous organic magnetoresistance from competing carrier-spin-dependent interactions with localized electronic and nuclear spins

Y. Wang·N. J. Harmon·K. Sahin-Tiras·M. Wohlgenannt·M. E. Flatté
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Abstract

We describe a new regime for low-field magnetoresistance in organic semiconductors, in which the spin-relaxing effects of localized nuclear spins and electronic spins interfere. The regime is studied by the controlled addition of localized electronic spins to a material that exhibits substantial room-temperature magnetoresistance ($\sim 20$\%). Although initially the magnetoresistance is suppressed by the doping, at intermediate doping there is a regime where the magnetoresistance is insensitive to the doping level. For much greater doping concentrations the magnetoresistance is fully suppressed. The behavior is described within a theoretical model describing the effect of carrier spin dynamics on the current.

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Y. Wang, N. J. Harmon, K. Sahin-Tiras, M. Wohlgenannt, M. E. Flatté. 2014-07-23. Anomalous organic magnetoresistance from competing carrier-spin-dependent interactions with localized electronic and nuclear spins. https://doi.org/10.1103/physrevb.90.060204

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