Theory of Spin Torque Assisted Thermal Switching of Single Free Layer

TL;DR

This paper presents a theoretical analysis of spin torque assisted thermal switching in single free layers, deriving formulas for switching currents and clarifying the correct exponent in the switching rate, impacting magnetic memory retention estimates.

Contribution

It provides a new theoretical derivation of switching current formulas and establishes that the exponent in the switching rate should be two, correcting previous assumptions.

Findings

Derived formulas for most likely and mean switching currents.

Showed the exponent in the switching rate formula is two.

Implications for accurate retention time estimation in MRAM.

Abstract

The spin torque assisted thermal switching of the single free layer was studied theoretically. Based on the rate equation, we derived the theoretical formulas of the most likely and mean switching currents of the sweep current assisted magnetization switching, and found that the value of the exponent $b$ in the switching rate formula significantly affects the estimation of the retention time of magnetic random access memory. Based on the Fokker-Planck approach, we also showed that the value of $b$ should be two, not unity as argued in the previous works.