Low-temperature resistivity anomaly and weak spin disorder in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi mathvariant="normal">C</mml:mi><mml:msub><mml:mi mathvariant="normal">o</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>MnGa</mml:mi></mml:mrow></mml:math> epitaxial thin films
Shucheng Tong, Xupeng Zhao, Dahai Wei, Jianhua Zhao
Abstract
The topological material of $\mathrm{C}{\mathrm{o}}_{2}\mathrm{MnGa}$ with potentially high spin polarization has attracted more and more attention, in the fields of fundamental science and spintronic applications. Here we report the electrical- and magnetotransport behaviors in epitaxial $\mathrm{C}{\mathrm{o}}_{2}\mathrm{MnGa}$ thin films. An angle-independent negative linear magnetoresistance and a negative anisotropy magnetoresistance are observed in the whole temperature range from 3 to 300 K, indicating the existence of weak spin disorder and a high spin polarization. Intriguingly, with decreasing temperature an anomalous resistivity upturn that exhibits $\ensuremath{-}{T}^{1/2}$ dependence is observed, and this phenomenon is robust under magnetic fields. Further analysis demonstrates that the three-dimensional enhanced electron-electron interaction effect is responsible for these phenomena rather than the orbital two-channel Kondo effect or other quantum interference effects, which provides deeper insight into the transport behavior of the $\mathrm{C}{\mathrm{o}}_{2}\mathrm{MnGa}$ materials.