Anisotropic transverse magnetoresistivity in α-YbAlB4

Abstract

We measured the transverse magnetoresistivity of the mixed valence compound α-YbAlB4. Two configurations were used where current was applied along [110] direction for both and magnetic field was applied along [-110] and c-axis. We found the transverse magnetoresistivity is highly anisotropic. In the weak field below 1 T, it is consistent with stronger c-f hybridization in the ab plane which was suggested from the previous zero field resistivity measurements. At the higher field above 3 T, we observed a negative transverse magnetoresistivity for the field applied along the c-axis. The temperature dependences of the resistivity measured at several different fields suggest the suppression of the heavy fermion behavior at the characteristic field of ∼ 5.5 T.