A solid state paramagnetic maser device driven by electron spin injection.
In response to an external, microwave-frequency magnetic field, a paramagnetic medium will absorb energy from the field that drives the magnetization dynamics. Here we describe a new process by which an external spin-injection source, when combined with the microwave field spin pumping, can drive the paramagnetic medium from one that absorbs microwave energy to one that emits microwave energy. We derive a simple condition for the crossover from absorptive to emissive behavior. Based on this process, we propose a solid-state, paramagnetic device in which microwave amplification by stimulated emission of radiation is driven by spin injection.
Watts
S M
SM
Physics of Nanodevices, Materials Science Centre, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
van Wees
B J
BJ