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

Abstract A breaking contact between two (La 0.7 Sr 0.3 )MnO 3 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 pronounced non-linear I – V characteristics when the break is arrested on a conductance plateau of nG 0 where 1⩽ n ⩽10. The data are fitted to I = AV + BV 3 where A ≈ nG 0 and B = A ν , where ν =0.72. Possible explanations will be considered in terms of blocked conductance channels, parallel metallic and tunnelling channels and the Luttinger liquid.