Evidence of rotational symmetry breaking in ScV₆Sn₆ from angle-dependent magnetoresistance measurements

It has been suggested that materials containing kagome lattices with van Hove singularities (vHs) near E_F are prone to electronic instability. The kagome material ScV₆Sn₆ presents an interesting counter example that hosts a charge density wave (CDW) with an ordering wave vector that cannot be related to the vHs in its band structure. Nevertheless, recent reports suggested that electronic nematicity might arise due to the vHs in this system. We have grown single crystals of ScV₆Sn₆ with residual resistivity ratios more than five times higher than in previous literature, allowing us to observe clear sixfold angular magnetoresistance oscillations while rotating field in the ab-plane up to temperatures above 200K. We show these oscillations are likely due to the large quasi-2D vHs hole pocket in this material. Notably, a twofold oscillations set in below 60K, well below T_CDW. We argue that this is evidence of rotational symmetry breaking of this large quasi-2D pocket arising from the instability of the vHs.