Berry-curvature-induced linear magnetotransport in magnetic Weyl semimetals

Abstract

Magnetotransport such as the giant magnetoresistance and Hall effect lies at the heart of fundamental physics and technologies. Recently, some experiments have clearly demonstrated linear magnetotransport (LMT) proportional to magnetic field but the underlying physical mechanism is still unclear. In this work, we show that Berry curvature effect is a new mechanism dominating the LMT. The Berry-curvature-induced LMT widely exists in 66 out of 122 magnetic point groups. For typical magnetic Weyl semimetals Co$_3$Sn$_2$S$_2$ and ferromagnetic MnBi$_2$Te$_4$, Berry curvature induces LMT conductivities reaching orders of $10^4$ and $10^2$ ${\rm \Omega^{-1}m^{-1}}$ per tesla, respectively, which are tunable through magnetization canting induced by moderate magnetic fields. We further reveal that Berry-curvature-induced LMT can be detected by Hall effect and especially intrinsic magnetoresistance exceeding $100\%$ per tesla insensitive to the sample quality. Our results agree with recent experiments and uncover the important role of Berry curvature in LMT.