Quasilinear quantum magnetoresistance and field-temperature scaling in pressure-induced nonsymmorphic superconductor CrAs*

The strongly correlated helimagnet CrAs undergoes a quantum phase transition to a nonmagnetic superconductor under pressure [1,2]. We have measured the transverse magnetoresistance of CrAs under pressure [3]. In the pressure range close to where the superconducting transition temperature is maximised, our low-temperature magnetoresistance exhibits a striking non-saturating, quasilinear magnetic field dependence up to 14 T. Our bandstructure calculations reveal a subtle band crossing near the Y-point of the Brillouin zone, which is protected by the nonsymmorphic crystal symmetry. In this presentation, I will show that the quasilinear magnetoresistance arises from an intricate interplay between the nontrivial band crossing and strong magnetic fluctuations. I will also discuss a field-temperature scaling of our data using a recently developed model [4]. Comparisons with the isostructural compound CrP will be made.
[1] H. Kotegawa et al., J. Phys. Soc. Jpn. 83, 093702 (2014)
[2] W. Wu et al., Nature Commun. 5, 6508 (2014)
[3] Q. Niu et al., Nature Commun. 8, 15358 (2017)
[4] I. M. Hayes et al., Nature Phys. 12, 916 (2016)