Thermal effects on the critical current of spin torque switching in spin valve nanopillars

Abstract

In spin valve nanopillars, temperature affects the spin torque reversal of the free magnetic layer. The authors compare values of zero temperature critical switching current Ic0 extrapolated from room temperature pulsed current switching measurements to those of quasistatic current sweeps at 5K. The values extrapolated from the room temperature pulsed switching probability measurements are always less than or equal to those of the low temperature quasistatic measurements. Further, the room temperature device-to-device variations of the critical switching current are drastically reduced at low temperature, where the Ic0 agrees with theory. Finally, the authors find that Ic0 scales with the free layer volume, as expected.