Non-linear I-V curves in nanocontacts between crystals of (La0.7Sr0.3)MnO3

A breaking contact between two (La0.7Sr0.3)MnO3 crystals can exhibit 20 or more conductance steps which occurs close to integral multiples of G(0) = 2 e(2)/h. This is in contrast to a breaking metal contact, where the nanowire shows only a few well-defined conducting steps. We have found very pronoun ced non-linear I-V characteristics when the break is arrested on a conducta nce plateau of nG(o) where 1 less than or equal to n less than or equal to 10. The data are fitted to I = AV + BV3 where A x nG(o) and B = A(v), where v = 0.72. Possible explanations will be considered in terms of blocked con ductance channels, parallel metallic and tunnelling channels and the Luttin ger liquid. (C) 2000 Elsevier Science B.V. All rights reserved.