Negative Magnetoresistance in the GeSn Strip

Discovery of topological materials associated with an exotic phenomenon has attracted increasing attention in modern condensed matter physics. A typical example is the chiral anomaly proposed in the Dirac or Weyl semimetals. In addition to the well-known topological semimetals, such as TaAs and Na3Bi, recently, group IV GeSn alloys were also proposed to be Dirac semimetals in theory, demonstrating potential applications compatible with current Si-based technology. Here, we report the observation of large negative magnetoresistance (MR) that is sensitive to the orientation of the magnetic and electric field in the GeSn strip. This negative MR emerges only when the applied magnetic field is parallel to the electric field, which is consistent with the chiral anomaly in topological semimetals. This work paves a new way toward exploring the negative MR behavior and underlying mechanism in a new class of Dirac semimetals.

Automated summary

This study reports the observation of large negative magnetoresistance in GeSn strips, which is sensitive to the orientation of the magnetic and electric field. The negative magnetoresistance only emerges when the applied magnetic field is parallel to the electric field, consistent with the chiral anomaly in topological semimetals. This work opens up a new way to explore the negative magnetoresistance behavior and underlying mechanism in a new class of Dirac semimetals.