The Nature of Extremely Large Nonsaturating Magnetoresistance in SrNbO₃-SrTiO₃ System

Understanding unconventional magnetoresistance (MR), such as negative longitudinal MR and non-saturating linear MR (LMR), gives deep insight into the electronic processes in a wide range of quantum materials including compensated semimetals, metals, and topological materials. However, the connection between MR and non-trivial topology is unclear. In this work, we observe LMR as high as 150,000% in the SrNbO₃-SrTiO₃ system with carrier density n~10²¹ cm^-3 and show that the LMR is a direct consequence of the high mobility of the coherent electronic system. By tuning the carrier density over two orders of magnitude via thickness control and tracking the onset field and temperature dependence of LMR, we find results are consistent with the semiclassical guiding center model [1]. Under this framework, the guiding centers travel along the equipotential lines of weakly disordered potentials while remaining coherent. A brief discussion along with the data will be presented in the talk.

[1] Justin C. et. al. Phys. Rev. B 92, 180204(R) (2015)