Fig. 2: Nonreciprocal angular magnetoresistance effects in SrMnBi2.
a SEM image of the micro-fabricated device of SrMnBi2. b Schematic illustration of the measurement of angular magnetoresistance effects of interlayer resistivity for the field rotating within the ab plane. c Azimuth-angle φ dependence of the first-harmonic interlayer resistivity \({\rho }_{zz}^{\omega }\) (upper) and the second-harmonic one \({\rho }_{zz}^{2\omega }\) (lower) at 1.5 K at 12 T, measured between the terminals 2–3. The magnitude and frequency of the applied current Iz were 200 μA and 23 Hz, respectively. The inset shows the relation between the field direction and Dirac valleys. d \({\rho }_{zz}^{2\omega }\) versus φ at 1.4 K at 12 T for various Iz. The dotted horizontal line is the baseline for each curve, which is determined as the average of the peak and dip values. Each curve is shifted for clarity. e Peak height of \({\rho }_{zz}^{2\omega }\) (\(\Delta {\rho }_{zz}^{2\omega }\) defined in panel d) versus Iz.
