Giant Linear Magnetoresistance and Carrier Density Tunable Transport in Topological Crystalline Insulator SnTe Thin Film

Carrier density control is of great importance to modulate the topological phase and topological transport for the topological crystalline insulators (TCIs). Here, the transport property modulation of TCI SnTe thin films grown on SrTiO3 (111) by tuning the carrier density is reported. The low temperature magneto-transport in a typical SnTe film with high hole carrier density in the as grown films exhibits a giant linear magnetoresistance (GLMR) effect (up to 1849% at 2K under 14T) and then the magnetoresistance becomes much weaker and weak anti-localization (WAL) appears in the same SnTe film by n-type doping in vacuum after aging 30 days. Alternatively, the hole carrier density of the as grown SnTe films is lowered by enhancing the growth temperature to promote Sn diffusion to reduce Sn vacancies and the as grown samples exhibit a WAL with two-dimensional (2D) characteristics. This work provides promising application for magnetoelectronic sensors and spintronics based on TCI SnTe thin film.