Organic magnetic-field-effect transistors and ultrasensitive magnetometers

We propose organic magetic-field-effect transistors and ultrasensitive magnetometers that exploit spin transport in organics and its sensitive dependence on a transverse magnetic field due to spin precession. The device design is based on experimentally observed magnetoresistance in magnet/polymer/magnet structures and on the theory of spin transport in these structures. It is shown that at room temperature the magnetometers are capable of detecting sub $nT$ magnetic fields, and the $I\text{–}V$ characteristics of the transistors can be strongly modified by magnetic fields of a few $\mathrm{G}$ with response times of a few ns.