| Author(s): |
Ion Garate; Keith Gilmore; Mark D. Stiles; Allan H. MacDonald; |
| Title: |
Non-Adiabatic Spin Transfer Torque in Real Materials |
| Published: |
March 16, 2009 |
| Abstract: |
The motion of simple domain walls and of more complex magnetic textures in the presence of a transport current is described by the Landau-Lifshitz-Slonczewski (LLS) equations. Predictions of the LLS equations depend sensitively on the ratio between the dimensionless material parameter β which characterizes non-adiabatic spin-transfer torques and the Gilbert damping parameter α. This ratio has been variously estimated to be close to 0, close to 1, and large compared to 1. By identifying β as the influence of a transport current on α, we derive a concise, explicit and relatively simple expression which relates β to the band structure and Bloch state lifetimes of a magnetic metal. Using this expression we demonstrate that intrinsic spin-orbit interactions lead to intra-band contributions to β which are often dominant and can be (i) estimated with some confidence and (ii) interpreted using the ``breathing Fermi surface'' model. |
| Citation: |
Physical Review B (Condensed Matter and Materials Physics) |
| Volume: |
79 |
| Issue: |
10 |
| Pages: |
15 pp. |
| Keywords: |
Spin-transfer torque, Magnetic damping, Magnetization dynamics, Adiabatic, Spin-orbit coupling, Domain wall, Spin current |
| Research Areas: |
Nanomagnetics |
| PDF version: |
 Click here to retrieve PDF version of paper (309KB) |
