755 research outputs found
Fermi surface topology and impurity-induced resonance state in BiS-based superconductors
Within the two-orbital model for BiS-based superconductors, the effect
from a single nonmagnetic impurity scattering on the superconducting-state is
investigated in terms of the T-matrix approach. By considering three kinds of
the typical Fermi surface topology which characterize the essential features of
the doping dependence of the electronic structure in BiS-based
superconductors, it is found that the impurity scattering on the
superconducting-state with the conventional -wave, the extended -wave,
the -wave, and the -wave symmetries induces
\textit{qualitatively} different resonance states due to the evolution of
unique nodal structures on the Fermi surface with doping. These
impurity-induced resonance states can be verified directly by the scanning
tunneling microscopy experiments, and therefore they are proposed as a probe of
the superconducting pairing symmetry in BiS-based superconductors.Comment: 5 pages, 7 figure
A proof of the strong no loop conjecture
The strong no loop conjecture states that a simple module of finite
projective dimension over an artin algebra has no non-zero self-extension. The
main result of this paper establishes this well known conjecture for finite
dimensional algebras over an algebraically closed field.Comment: 9 page
- …