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Cover Picture: Organic magnetoresistance and spin diffusion in organic semiconductor thin film devices (Phys. Status Solidi RRL 6/2012)
Author(s) -
Wohlgenannt Markus
Publication year - 2012
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Reports
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201290013
Subject(s) - spintronics , hyperfine structure , quantum decoherence , condensed matter physics , magnetoresistance , organic semiconductor , spin (aerodynamics) , precession , coupling (piping) , spin engineering , semiconductor , materials science , ferromagnetism , physics , optoelectronics , magnetic field , spin polarization , electron , quantum mechanics , quantum , metallurgy , thermodynamics
Magnetic field sensors that use ferromagnetic layers to achieve spin‐polarized currents are used, e.g., as read heads in hard disk drives. However, the potential applications of the underlying spin‐physics may extend far beyond read heads, and eventually we may have semiconductor logic gates based on spin‐dependent processes (semiconductor spintronics). On pp. 229–242 , Markus Wohlgenannt reviews recent efforts to use organic conjugated compounds for semiconductor spintronics. These organic compounds offer potentially very long spin‐decoherence times. The cover figure shows one of the proposed decoherence mechanisms, resulting from hyperfine coupling. Hyperfine coupling can be envisioned as the precession of an electron spin about the molecular hyperfine field, which is a quasi‐classical magnetic field that points in a different direction on each molecule. Hyperfine coupling is important also for the so‐called Organic Magneto¬resistive Effect (OMAR), which is a large, room‐temperature magnetoresistive effect that occurs even in organic devices that do not use any magnetic materials. The cover page indicates typical OMAR traces measured in organic devices.