Examples

# Principal Layer Green’s Functions

Many spintronic devices to emerge in recent years consist of spin transport through alternating, nanosized metallic layers

Junctions between these layers plays an essential role in controlling the spin current. Many of these devices rely on spin-orbit coupling, which can cause spins to rotate or flip. Spin flip scattering at the interface thus plays an important role in these devices. Scattering is usually deleterious to device operation because it results in loss of spin coherence that underpins the device. This loss is typically quantified experimentally by measuring the spin flipping probability $P = 1 - \exp ( - \delta )$. The spin loss of the interface is then parameterised by δ. It was widely assumed that δ was proportional to the spin-flip scattering probability of an individual interface.

In a recent paper PRL 117, 207204 we show that δ is proportional to the *square root* of the spin flip scattering probability, rather than the probability itself. To buttress the theory, direct calculations of spin flip loss where calculated for the Cu/Pd interface within the Landauer-Büttiker formalism, using the **lmpg** code.

The figure shows spin-conserving and spin-flip transmittances T_{↑↑} and T_{↑↓} and corresponding reflectances R_{↑↓}, R_{↑↓} for the Cu/Pd (111) interface, calculated by **lmpg**. The direct calculations of δ matched measurements reasonably well.