Thermally-Assisted Spin-Transfer Torque Magnetization Reversal in Uniaxial Nanomagnets

Abstract

We simulate the stochastic Landau-Lifshitz-Gilbert (LLG) dynamics of a uniaxial nanomagnet out to sub-millisecond timescales using a graphical processing unit based micromagnetic code and determine the effect of geometrical tilts between the spin-current and uniaxial anisotropy axes on the thermally assisted reversal dynamics. The asymptotic behavior of the switching time ($I\to 0$, $<\tau >\propto \exp (-\xi (1-I{)}^2)$) is approached gradually, indicating a broad crossover regime between ballistic and thermally assisted spin transfer reversal. Interestingly, the mean switching time is shown to be nearly independent of the angle between the spin current and magnet's uniaxial axes. These results have important implications for modeling the energetics of thermally assisted magnetization reversal of spin transfer magnetic random access memory bit cells.

4 pages, 2 figures

References in corpus (5)

• Thermally assisted magnetization reversal in the presence of a spin-transfer torque
• Nonequilibrium quantum criticality in open electronic systems
• Spin-torque switching: Fokker-Planck rate calculation
• Spin-transfer pulse switching: From the dynamic to the thermally activated regime
• Thermally assisted spin transfer torque switching in synthetic free layers

Cited by in corpus (9)

• Magnetization dynamics: path-integral formalism for the stochastic Landau-Lifshitz-Gilbert equation
• Thermally-Assisted Spin-Transfer Torque Dynamics in Energy Space
• Spin torque switching of an in-plane magnetized system in a thermally activated region
• Thermally activated switching rate of a nanomagnet in the presence of spin torque
• Spin-Transfer Torque Magnetization Reversal in Uniaxial Nanomagnets with Thermal Noise
• Thermally-Assisted Spin-Transfer Torque Magnetization Reversal of Uniaxial Nanomagnets in Energy Space
• Current dependence of spin torque switching rate based on Fokker-Planck approach
• Influence of Quantum and Thermal Noise on Spin-Torque-Driven Magnetization Switching
• Switching time of spin-torque-driven magnetization in biaxial ferromagnets