Figure 3: Angular dependence.

(a) In-plane resistivity as a function of the magnetic field at 380 mK, for various field angles relative to the c axis, that is, from 0° (=H||c) to 65° as the field is rotated towards the b-direction. The field remained perpendicular to the applied current in a transverse magnetoresistance configuration at all studied angles. The drop at lower fields appears reproducibly at the transition field H_c under all experimental conditions. The position in field of the jump from the low resistance into the high-resistance state at higher fields, however, depends on external conditions such as the applied current, field sweep rate and angle. The largest hysteresis was obtained by using slow field sweep rates (1 T min⁻¹) and low currents (400 μA). Nevertheless, jumps to intermediate resistivity values were observed, especially at higher angles. (b) Field position of the drop from the high- into the low-resistance state (H_c, marked by arrows in a), as well as the height of the drop relative to the low-resistivity branch. The lowest transition field is observed for fields along the c axis, and the transition field increases on tilting the field towards the b-direction until θ~60°, above which no transition is observable. The relative height of the drop is difficult to define with precision due to the resistance oscillations in the high-field state arising from the angle-dependent Shubnikov–de Haas effect. The relative drop is maximal at around 20° away from c axis and decays on further rotation of the field away from the c axis, until the transition becomes undetectable at ~60°.