Year: 1997
Type: article
Abstract: We calculate the electronic polarizability of the superconducting state near extremum vectors ${\stackrel{\ensuremath{\rightarrow}}{Q}}_{0}$ of the Fermi surface. A pole appears in the polarizability at frequencies $\ensuremath{\omega}$ near the superconducting gap $2\ensuremath{\Delta}$ which leads to a sharp peak in the spectral function for the lattice vibrations near ${\stackrel{\ensuremath{\rightarrow}}{Q}}_{0}$ at $\ensuremath{\omega}$ just below $2\ensuremath{\Delta}$. A second order transition to a charge density wave state below the superconducting transition is shown to be unlikely. The results are compared with the recent inelastic neutron scattering measurements in compounds, $A{\mathrm{Ni}}_{2}{\mathrm{B}}_{2}\mathrm{C}$, $A\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\mathrm{Y}$ or $\mathrm{Lu}$.
Source: Physical Review Letters
Authors: Hae-Young Kee, C. Varma
Institution: Rutgers, The State University of New Jersey
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1964686578