Non-Fermi liquid ground state in magnetic multilayers tuned by electric and magnetic fields

We report on anomalous electron transport properties of low dimentional mag netic systems which may be tuned by electric and magnetic fields. In magnet ic trilayers Co/M/Co (M - nonmagnetic spacer), which have been used to reve al the ground state of a disordered two-dimentional metal, at lower tempera tures the crossover from a logarithmic to an anomalous non-Fermi liquid beh aviour (Delta rho similar to beta root T) is observed which is interpreted as due to scattering of the electrons by symmetrical two-level tunnelling s ystems. We have also demonstrated that classical magnetic multilayers [Fe/C r](10) with enhanced spin dependent scattering effect may be used to study quantum magnetic phase transitions from ferromagnet to antiferromagnet. (C) 1999 Published by Elsevier Science B.V. All rights reserved.