Editing Spintronics (section)

=== [[Spin Torque]] ===
The spin transfer torque, which describes the transfer of spin angular momentum from a spin current to the magnetization of a material, is given by:

<math>
\mathbf{\tau}_{ST} = \frac{\hbar}{2e} \frac{\mathbf{J}_s \times \mathbf{M}}{M_s}
</math>

where:
* <math>\mathbf{\tau}_{ST}</math> is the spin torque,
* <math>\hbar</math> is the reduced Planck constant,
* <math>e</math> is the elementary charge,
* <math>\mathbf{J}_s</math> is the spin current density,
* <math>\mathbf{M}</math> is the magnetization vector,
* <math>M_s</math> is the saturation magnetization.