Pressure-induced reconstitution of Fermi surfaces and spin fluctuations in S-substituted FeSe.

ABSTRACT: FeSe is a unique high-[Formula: see text] iron-based superconductor in which nematicity, superconductivity, and magnetism are entangled with each other in the P-T phase diagram. We performed [Formula: see text]Se-nuclear magnetic resonance measurements under pressures of up to 3.9 GPa on 12% S-substituted FeSe, in which the complex overlap between the nematicity and magnetism are resolved. A pressure-induced Lifshitz transition was observed at 1.0 GPa as an anomaly of the density of states and as double superconducting (SC) domes accompanied by different types of antiferromagnetic (AF) fluctuations. The low-[Formula: see text] SC dome below 1 GPa is accompanied by strong AF fluctuations, whereas the high-[Formula: see text] SC dome develops above 1 GPa, where AF fluctuations are fairly weak. These results suggest the importance of the [Formula: see text] orbital and its intra-orbital coupling for the high-[Formula: see text] superconductivity.

SUBMITTER: Kuwayama T 

PROVIDER: S-EPMC8390510 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature