Fermi surface revolution in CeRhIn 5 and non-centrosymmetric superconductivity in CeIrSi 3

Abstract

Revolution of the pressure-induced heavy fermion state and superconductivity in an antiferromagnet CeRhIn 5 have been established by high-pressure Fermi surface studies using the de Haas–van Alphen technique. A marked change of the 4f-electron nature from localized to itinerant is realized at a critical pressure P c ≃ 2.35 GPa under magnetic fields, together with a divergent tendency of the cyclotron mass at P c . The electronic state of CeIrSi 3 with the non-centrosymmetric tetragonal structure is also tuned from the antiferromagnetic state to the superconducting state as a function of pressure. The upper critical field H c 2 ( 0 ) at pressure of 2.65 GPa is found to be highly anisotropic: H c 2 ( 0 ) = 95 kOe for H ∥ [ 1 1 0 ] and H c 2 ( 0 ) ≃ 300 kOe for H ∥ [ 0 0 1 ] , with the superconducting transition temperature T sc = 1.6 K . A large magnitude of H c 2 ( 0 ) and a large anisotropy of H c 2 ( 0 ) are characteristic, which reveals a new type of superconductivity closely related to the spin–orbit interaction based on the non-centrosymmetric crystal structure.