364 research outputs found
Pseudogap effects on the c-axis charge dynamics in copper oxide materials
The c-axis charge dynamics of copper oxide materials in the underdoped and
optimally doped regimes has been studied by considering the incoherent
interlayer hopping. It is shown that the c-axis charge dynamics for the chain
copper oxide materials is mainly governed by the scattering from the in-plane
fluctuation, and the c-axis charge dynamics for the no-chain copper oxide
materials is dominated by the scattering from the in-plane fluctuation
incorporating with the interlayer disorder, which would be suppressed when the
holon pseudogap opens at low temperatures and lower doping levels, leading to
the crossovers to the semiconducting-like range in the c-axis resistivity and
the temperature linear to the nonlinear range in the in-plane resistivity.Comment: 21 pages, Revtex, Six figures are include
NMR evidence of strong-correlated superconductivity in LiFeAs: tuning toward an SDW ordering
In this letter, we reported the results of NMR study on LiFeAs single
crystals. We find a strong evidence of the low temperature spin fluctuations;
by changing sample preparation conditions, the system can be tuned toward an
spin-density-wave (SDW) quantum-critical point. The detection of an
interstitial Li(2) ion, possibly locating in the tetrahedral hole, suggests
that the off-stoichiometry and/or lattice defect can probably account for the
absence of the SDW ordering in LiFeAs. These facts show that LiFeAs is a
strongly correlated system and the superconductivity is likely originated from
the SDW fluctuations.Comment: 5 pages, s figure
- …