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A researcher whose work with Alain Schuhl explains giant magnetoresistance through spin-dependent conduction in magnetic multilayers. In the Mott two-current model, the two electron spin channels can carry electric current with different resistances. Changing the relative magnetization directions of adjacent layers changes how strongly each channel is scattered. Their treatment connects microscopic scattering with a measurable resistance change and makes explicit the assumptions needed to treat the spin channels independently.^[ref]

The Mott two-current model treats the two spin populations as parallel conduction channels when spin-flip scattering is weak. Thus $\sigma ={\sigma }_{\uparrow }+{\sigma }_{\downarrow }$ and ${\rho }^{-1}={\rho }_{\uparrow }^{-1}+{\rho }_{\downarrow }^{-1}$. Light, broad-band carriers conduct efficiently; scattering into narrow $d$-like states relaxes their current. In a simple spin-conserving $s$–$d$ picture,In copper, the filled $d$ bands supply little final-state phase space at $E_F$, so both spin channels have low resistivity. In cobalt, the nearly filled majority $d$ band suppresses majority-channel scattering, while minority $d$ states remain available. The stated iron reversal corresponds to stronger scattering-weighted majority-channel phase space: its majority $d$ band is not closed as in cobalt. Band filling, exchange splitting, velocities and scattering matrix elements set this scattering-weighted spin-channel asymmetry; majority population alone does not select the better conductor. The given iron ordering is a material/scattering input, not a universal consequence of the two-current postulate. Different impurities and interfaces can change the asymmetry.^[ref]

Alain Schuhl and Daniel Lacour's authored article in C. R. Physique6,pp.945–955. Section2.1 discusses Mott two-current model transport parameters and the spin asymmetry of defect scattering;§2.2 describes averaging scattering when carriers sample several layers. This supports the model qualifications without asserting a universal iron channel ordering.