  Magnetic and spin-based technologies for data storage and processing pose
unique challenges for information transduction to light because of magnetic
metals' optical loss, and the inefficiency and resistivity of semiconductor
spin-based emitters at room temperature. Transduction between magnetic and
optical information in typical organic semiconductors poses additional
challenges as the Faraday and Kerr magnetooptical effects rely on the
electronic spin-orbit interaction, and the spin-orbit interaction in organics
is weak. Other methods of coupling light and spin have emerged in organics,
however, as the spin-dependent character of exciton recombination, with spin
injection from magnetic electrodes, provides magnetization-sensitive light
emission, although such approaches have been limited to low temperature and low
polarization efficiency. Here we demonstrate room temperature information
transduction between a magnet and an organic light emitting diode that does not
require electrical current, based on control via the magnet's remanent field of
the exciton recombination process in the organic semiconductor.
