2017/10/18 by Naoki Fujiwara, Naoto Kawaguchi, Soshi Iimura +3
Business, Management and Accounting · Materials Science · Physics and Astronomy · #Antiferromagnetism #Condensed matter physics #Corporate Taxation and Avoidance #Doping #Iron-based superconductors research #Materials science #Paramagnetism #Phase (matter) #Phase diagram #Phase transition #Physics #Quantum critical point #Quantum mechanics #Quantum phase transition #Rare-earth and actinide compounds #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.96.140507
arxiv created 2017/10/18 · openalex publication_date 2017/10/30 · arxiv updated 2017/11/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Hydrogen (H)-doped LaFeAsO is a prototypical iron-based superconductor. However, its phase diagram extends beyond the standard framework, where a superconducting (SC) phase follows an antiferromagnetic (AF) phase upon carrier doping; instead, the SC phase is sandwiched between two AF phases appearing in lightly and heavily H-doped regimes. We performed nuclear magnetic resonance (NMR) measurements under pressure, focusing on the second AF phase in the heavily H-doped regime. The second AF phase is strongly suppressed when a pressure of 3.0 GPa is applied, and apparently shifts to a highly H-doped regime, thereby a ``bare'' quantum critical point (QCP) emerges. A quantum critical regime emerges in a paramagnetic state near the QCP, however, the influence of the AF critical fluctuations to the SC phase is limited in the narrow doping regime near the QCP. The optimal SC condition (Tc\ensuremath∼48 K) is unaffected by AF fluctuations.