Fig. 1: Planar Hall Effect (PHE) and Planar Anisotropic Magnetoresistance (PAMR) of CeCo₂Ga₈.

a Sketch of PHE [\({\rho }_{xz}^{{{{\rm{PHE}}}}}(\varphi )\)] and PAMR [ρ_zz(φ)] measurements. φ characterizes the angle spanned by electrical current j and external magnetic field B. The sample investigated is prepared by focused ion beam (FIB) with j∥ [001], and the rotation of B is within ac plane. b Crystalline structure of CeCo₂Ga₈ which shows quasi-1D cerium chain along [001]. c Temperature dependence of resistivity ρ_zz. The onset of Kondo effect is denoted by \({T}_{K}^{on}\approx 100\) K, and the Kondo coherence develops below T^* ≈ 12 K where ρ_zz peaks. The red dashed line is a fit to the \(-\log T\) law in the incoherent regime. d \({\rho }_{xz}^{{{{\rm{PHE}}}}}(\varphi )\) at 1.6 K. The symbols represent experimental data, while the solid line is the fitting curve. e ρ_zz(φ) at 1.6 K. f and g respectively show \({\rho }_{xz}^{{{{\rm{PHE}}}}}(\varphi )\) and ρ_zz(φ) in polar coordinates that exhibit two-fold oscillations. The color bars signify the values of \({\rho }_{xz}^{{{{\rm{PHE}}}}}(\varphi )\) and ρ_zz(φ).