Anomalous electron transport in magnetic multilayers tuned by electric andmagnetic fields

We report on anomalous quantum electron transport in low dimensional system s which may be tuned by varying electric and magnetic fields. In magnetic t rilayers Co/M/Co (M- nonmagnetic metallic spacer), which have been used to reveal ground state of disordered two-dimensional metal at low temperatures a crossover fr om the logarithmic to the anomalous non-Fermi liquid behavi or (Delta rho similar to beta*root T) is observed This crossover is probabl y due to scattering of electrons by symmetrical two-level systems. We also demonstrate that magnetic multilayers, with enhanced spin dependent scatter ing effects, may be used to study quantum magnetic phase (QPT) transition p henomena. We observed that through phase transition from antiferromagnet to the ferromagnet induced by magnetic field the spin-dependent contribution to the resistivity varies as Delta rho(S) similar to T-alpha with alpha=f(H ). In the vicinity of QPT, the spin dependent contribution to the resistivi ty varies linearly with temperature. (C) 1999 Acta Metallurgica Inc.