Unusual dependence of resistance and voltage noise on current in La1-xSrxMnO3 ultrathin films

We report on measurements of current-resistance effects in La1-xSrxMnO3 ultrathin films deposited by molecular beam epitaxy. dc transport and voltage noise spectral density analyses have been performed in the temperature range of 10-300 K, and the results are compared with existing theoretical models. A possible connection between the explanation of the electrical transport properties and the two-level tunneling systems model, used for the voltage noise analysis, is proposed.