TY - JOUR
T1 - Averaged equation for energy diffusion on a graph reveals bifurcation diagram and thermally assisted reversal times in spin-torque driven nanomagnets
AU - Newhall, Katherine A.
AU - Vanden-Eijnden, Eric
N1 - Funding Information:
We would like to thank Dan Stein and Andy Kent for useful discussions. The research of E.V.-E. was supported in part by NSF Grant DMS07-08140 and ONR Grant N00014-11-1-0345.
PY - 2013/5/14
Y1 - 2013/5/14
N2 - Driving nanomagnets by spin-polarized currents offers exciting prospects in magnetoelectronics, but the response of the magnets to such currents remains poorly understood. We show that an averaged equation describing the diffusion of energy on a graph captures the low-damping dynamics of these systems. From this equation we obtain the bifurcation diagram of the magnets, including the critical currents to induce stable precessional states and magnetization switching, as well as the mean times of thermally assisted magnetization reversal in situations where the standard reaction rate theory of Kramers is no longer valid. These results match experimental observations and give a theoretical basis for a Néel-Brown-type formula with an effective energy barrier for the reversal times.
AB - Driving nanomagnets by spin-polarized currents offers exciting prospects in magnetoelectronics, but the response of the magnets to such currents remains poorly understood. We show that an averaged equation describing the diffusion of energy on a graph captures the low-damping dynamics of these systems. From this equation we obtain the bifurcation diagram of the magnets, including the critical currents to induce stable precessional states and magnetization switching, as well as the mean times of thermally assisted magnetization reversal in situations where the standard reaction rate theory of Kramers is no longer valid. These results match experimental observations and give a theoretical basis for a Néel-Brown-type formula with an effective energy barrier for the reversal times.
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U2 - 10.1063/1.4804070
DO - 10.1063/1.4804070
M3 - Article
AN - SCOPUS:84878046500
SN - 0021-8979
VL - 113
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 18
M1 - 184105
ER -