Superconductivity and Magnetism in Noncentrosymmetric RhGe

Abstract

RhGe synthesized at high pressure is crystallized in noncentrosymmetric cubic structure of the B20 type. Measurements of the electrical resistivity and magnetization demonstrate a superconducting state below T${}_c$ ~ 4.5 K and a weak ferromagnetism below T${}_m$ ~ 140 K. Specific heat data confirm the bulk nature of superconductivity in this ferromagnetic superconductor. The superconducting region forms a dome on the P-T diagram with a maximum of T${}_c$ near 4 GPa. Ab initio simulations suggest that the observed weak magnetization emerges from the pronounced spin polarization with magnetic quadrupole and toroidal moments located at Rh and Ge sites.

9 pages, 8 figures