Giant Negative Magnetoresistance beyond Chiral Anomaly in Topological Material YCuAs 2

Large negative magnetoresistance (MR) effect, which usually emerges in various magnetic systems, is a technologically important property for spintronics. Recently, the so-called "chiral anomaly" in topological semimetals offers an alternative to generate considerable negative MR effect without utilizing magnetism. However, it requires that the applied magnetic field must be strictly along the electric current direction, which sets a strong limit for practical applications. Here, we discover a giant negative MR effect with a value of up to -40% in 9 T at 2 K in a nonmagnetic Dirac material YCuAs , which is not restricted to the specific configuration for applied magnetic fields. Based on magnetic susceptibility and nuclear magnetic resonance measurements, the giant negative MR effect is tightly connected with the unexpected spin-dependent scattering from vacancy-induced local moments, which is also beyond classical Kondo effect. The present work not only offers an alternative route for spintronics based on nonmagnetic topological materials, but also helps to further understand the negative MR effect in topological materials. This article is protected by copyright. All rights reserved.