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

作者:Wang Y*; Harmon N J; Sahin Tiras K; Wohlgenannt M; Flatte M E
来源:Physical Review B, 2014, 90(6): 060204.
DOI:10.1103/PhysRevB.90.060204

摘要

We describe a 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 (similar to 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.

  • 出版日期2014-8-21