Pseudogap Behavior of the Nuclear Spin-lattice Relaxation Rate in FeSe Probed by ${}^{77}$Se-NMR

Abstract

We conducted ${}^{77}$Se-nuclear magnetic resonance studies of the iron-based superconductor FeSe in magnetic fields of 0.6 to 19 T to investigate the superconducting and normal-state properties. The nuclear spin-lattice relaxation rate divided by the temperature $(T_{1}T{)}^{-1}$ increases below the structural transition temperature $T_{\mathrm{s}}$ but starts to be suppressed below $T^{\ast }$, well above the superconducting transition temperature $T_{\mathrm{c}}(H)$, resulting in a broad maximum of $(T_{1}T{)}^{-1}$ at $T_{\mathrm{p}}(H)$. This is similar to the pseudogap behavior in optimally doped cuprate superconductors. Because $T^{\ast }$ and $T_{\mathrm{p}}(H)$ decrease in the same manner as $T_{\mathrm{c}}(H)$ with increasing $H$, the pseudogap behavior in FeSe is ascribed to superconducting fluctuations, which presumably originate from the theoretically predicted preformed pair above $T_{\mathrm{c}}(H)$.

10 pages, 4 figures

References in corpus (9)

• To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report
• The Structural Phase Transition in FeSe (Fe1+dSe)
• Orbital-driven nematicity in FeSe
• Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
• Emergence of the nematic electronic state in FeSe
• Reconstruction of Band Structure Induced by Electronic Nematicity in an FeSe Superconductor
• Origin of the tetragonal-to-orthorhombic (nematic) phase transition in FeSe: a combined thermodynamic and NMR study
• Giant superconducting fluctuations in the compensated semimetal FeSe at the BCS-BEC crossover
• Quasiparticle Excitations in the Superconducting State of FeSe Probed by Thermal Hall Conductivity in the Vicinity of the BCS-BEC Crossover

Cited by in corpus (8)

• Exotic Superconducting States in FeSe-based Materials
• Quantum vortex core and missing pseudogap in the multi-band BCS-BEC-crossover superconductor FeSe
• Spin fluctuations from Bogoliubov Fermi surfaces in the superconducting state of S-substituted FeSe
• Inhomogeneous Knight shift in vortex cores of superconducting FeSe
• Pseudogap and Strong Pairing Induced by Incipient and Shallow Bands in the Quasi-Two-Dimensional KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Interrelationships between nematicity, antiferromagnetic spin fluctuations and superconductivity: Role of hotspots in FeSe${}_{1-x}$S${}_x$ revealed by high pressure ${}^{77}$Se NMR study
• Studies of superconductivity of Fe chalcogenides in films grown by PLD technique
• Quasiparticle interaction originating from Bogoliubov Fermi Surfaces under pressure in 18%-S substituted FeSe studied via NMR