Side-jump mechanism for the Hall effect of ferromagnets

The center of mass of a wave packet undergoes a discontinuous and finite sideways displacement on scattering by a central potential, in the presence of spin-orbit interaction. This is the main Hall-effect mechanism (rho(H)proportional to rho(2)) for Fe, Ni, and their alloys above 100 K, while asymmetric scattering dominates below 100 K. Displacement Ay per actual collision is calculated by partial waves. In the case of Born expansion, the leading term of Delta y or rho H/rho(2) is of zero order in the scattering potential. The magnitude is predicted correctly (Delta y approximate to 10(-10)-10(-11) m) when using the effective spin-orbit Hamiltonian derived by Fivaz from spin-orbit interband mixing. The calculation Of rho(H) is extended to arbitrary omega(c)tau for compensated and uncompensated metals. Other nonclassical physical mechanisms proposed by Karplus and Luttinger and by Doniach and by Fivaz are spurious for the dc Hall effect.