Quantum mechanics and spin-valves

Spin-valves comprising alternating nanoscale layers of FMs separated by NM spacers are thought to produce parallel electron-spins that lower the giant magneto-resistance of the disordered state known as the GMR, the change in resistance allowing data storage in magnetic recording. FM stands for ferromagnetic and NM for non-magnetic. Spin-valve theory is based on theoretical predictions made over a decade ago, but the mechanism by which spins align is not well understood, if indeed spins are the mechanism for lowering the GMR. The question is whether switching in spin-valves is caused by another mechanism. In this regard, QED induced conductivity is proposed as the resistive switching mechanism. QED stands for quantum electrodynamics. Finding basis in QM that precludes the atoms in submicron FM layers from having the heat capacity to conserve Joule heat by an increase in temperature, conservation proceeds by QED induced frequency up-conversion of Joule heat to non-thermal EM radiation at the TIR resonance of the FM. QM stands for quantum mechanics, EM for electromagnetic, and TIR for total internal reflection. The EM radiation has sufficient Planck energy to create excitons (holon and electron pairs) that as charge carriers significantly lower the GMR by the dramatic increase the conductivity of the FM layers. Extensions of QED induced conductivity in spin-valves to memristors, PCRAM films, and 1/f noise in nanowires are briefly summarized.