38,547 research outputs found
Hot Spots on the Fermi Surface of Bi2212: Stripes versus Superstructure
In a recent paper Saini et al. have reported evidence for a pseudogap around
(pi,0) at room temperature in the optimally doped superconductor Bi2212. This
result is in contradiction with previous ARPES measurements. Furthermore they
observed at certain points on the Fermi surface hot spots of high spectral
intensity which they relate to the existence of stripes in the CuO planes. They
also claim to have identified a new electronic band along Gamma-M1 whose one
dimensional character provides further evidence for stripes. We demonstrate in
this Comment that all the measured features can be simply understood by
correctly considering the superstructure (umklapp) and shadow bands which occur
in Bi2212.Comment: 1 page, revtex, 1 encapsulated postscript figure (color
Single crystal growth and physical properties of SrFe(AsP)
We report a crystal growth and physical properties of
SrFe(AsP). The single crystals for various s were
grown by a self flux method. For , reaches the maximum value of
30\,K and the electrical resistivity () shows -linear dependence.
As increases, decreases and () changes to -behavior,
indicating a standard Fermi liquid. These results suggest that a magnetic
quantum critical point exists around .Comment: 4 pages, 4 figures, accepted to Supplemental issue of the Journal of
Physical Society of Japan (JPSJ
Superconducting gap symmetry of Ba0.6K0.4Fe2As2 studied by angle-resolved photoemission spectroscopy
We have performed high-resolution angle-resolved photoemission spectroscopy
on the optimally-doped BaKFeAs compound and determined
the accurate momentum dependence of the superconducting (SC) gap in four
Fermi-surface sheets including a newly discovered outer electron pocket at the
M point. The SC gap on this pocket is nearly isotropic and its magnitude is
comparable ( 11 meV) to that of the inner electron and hole
pockets (12 meV), although it is substantially larger than that of the
outer hole pocket (6 meV). The Fermi-surface dependence of the SC gap
value is basically consistent with () = coscos
formula expected for the extended s-wave symmetry. The observed finite
deviation from the simple formula suggests the importance of multi-orbital
effects.Comment: 4 pages, 3 figures, 1 tabl
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