Abstract
Recent discovery of longitudinal negative magnetoresistance in topological semimetals has attracted a lot of attentions. The origin of negative magnetoresistance in topological semimetals is frequently attributed to the chiral anomaly associated with the emergence of Weyl semimetal phase. Besides topological semimetals, a negative longitudinal magnetoresistance has also been observed in BixSb1-x alloy around its topological phase transition point from a topological insulator to a normal insulator [Phys. Rev. Lett. 111, 246603 (2013)]. However, starting from an effective model which can describe the system around its topological phase transition point, we show that the chiral anomaly is unlikely to exist in this system except for the critical point. Therefore, other possible causes for the negative magnetoresistance in this system is waiting for exploration.
In this research, we plan to figure out in what conditions that the negative longitudinal magnetoresistance can appear, and to unveil the possible underlying mechanisms for the negative magnetoresistance based on the effective model. The conductance of the model in a magnetic field will be calculated by linear response theory. Our research may provide new insight into the mechanisms of the negative magnetotransport.
Anyone interested is welcome to attend.