The out-of-plane magnetoresistance of a $\mathrm{LaAl}{\mathrm{O}}_3$/$\mathrm{SrTi}{\mathrm{O}}_3$ interface is commonly positive due to significant orbital effect. In this paper, a large negative magnetoresistance is observed at a $\mathrm{LaAl}{\mathrm{O}}_3$ and Fe-doped $\mathrm{SrTi}{\mathrm{O}}_3$ interface upon the application of an out-of-plane magnetic field. Such large negative magnetoresistance is attributed to enhanced two-dimensional weak localization and Kondo effect. We think that these two effects are mainly the consequences of intentional Fe dopants in the substrate, which introduce holes, disorders, and spin scattering centers into the electronically conducting interface, directly modifying the spin-orbit coupling, orbital effect, scale of electrons motion, and local magnetic moments at the $\mathrm{LaAl}{\mathrm{O}}_3$/$\mathrm{SrTi}{\mathrm{O}}_3$ interface. The ${\mathrm{LaAlO}}_3\text{/Fe-doped}{\mathrm{SrTiO}}_3$ interfacial system provides a prospective platform for studying quantum interference between strongly correlated electrons. The substrate doping method may facilitate the application of $\mathrm{LaAl}{\mathrm{O}}_3$/$\mathrm{SrTi}{\mathrm{O}}_3$ interfaces in versatile electronic devices.

• Received 25 April 2018
• Revised 26 July 2018

DOI:https://doi.org/10.1103/PhysRevB.98.085305