M. Khodas, A. Levchenko, G. Catelani
We study the transport in ultrathin disordered film near the quantum critical
point induced by the Zeeman field. We calculate corrections to the normal state
conductivity due to quantum pairing fluctuations. The fluctuation-induced
transport is mediated by virtual rather than real quasi-particles. We find that
at zero temperature, where the corrections come from purely quantum
fluctuations, the Aslamazov-Larkin paraconductivity term, the Maki-Thompson
interference contribution and the density of states effects are all of the same
order. The total correction leads to the negative magnetoresistance. This
result is in qualitative agreement with the recent transport observations in
the parallel magnetic field of the homogeneously disordered amorphous films and
superconducting two-dimensional electron gas realized at the oxide interfaces.
View original:
http://arxiv.org/abs/1202.5082
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