Symmetry dependence of phonon lineshapes in superconductors with anisotropic gaps

Abstract

The temperature dependence below $T_c$ of the lineshape of optical phonons of different symmetry as seen in Raman scattering is investigated for superconductors with anisotropic energy gaps. It is shown that the symmetry of the electron-phonon vertex produces non-trivial couplings to an anisotropic energy gap which leads to unique changes in the phonon lineshape for phonons of different symmetry. The phonon lineshape is calculated in detail for $B_{1g}$ and $A_{1g}$ phonons in a superconductor with $d_{x^2-y^2}$ pairing symmetry. The role of satellite peaks generated by the electron-phonon coupling are also addressed. The theory accounts for the substantial phonon narrowing of the $B_{1g}$ phonon, while narrowing of the $A_{1g}$ phonon which is indistinguishable from the normal state is shown, in agreement with recent measurements on BSCCO.

15 pages (3 Figures available upon request), Revtex, 17

Cited by in corpus (11)

• Electronic Raman scattering in superconductors as a probe of anisotropic electron pairing
• Charge transfer fluctuation, $d-$wave superconductivity, and the $B_{1g}$ Raman phonon in the Cuprates: A detailed analysis
• Phonon anomalies in pure and underdoped R{1-x}K{x}Fe{2}As{2} (R = Ba, Sr) investigated by Raman light scattering
• Raman-Scattering Detection of Nearly Degenerate $s$-Wave and $d$-Wave Pairing Channels in Iron-Based Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ and Rb${}_{0.8}$Fe${}_{1.6}$Se${}_2$ Superconductors
• Spin-Phonon Coupling in the Single-Layer Extended t-J Model
• Role of the E2g phonon in the superconductivity of MgB2: a Raman scattering study
• Electronic and phononic Raman scattering in detwinned YBa${}_2$Cu${}_3$O${}_{6.95}$ and Y${}_{0.85}$Ca${}_{0.15}$Ba${}_2$Cu${}_3$O${}_{6.95}$: s-wave admixture to the $d_{x^2-y^2}$-wave order parameter
• Electron-phonon coupling in cuprate and iron-based superconductors revealed by Raman scattering
• Raman scattering in iron-based superconductors
• Screening in (d+s)-wave superconductors: Application to Raman scattering
• Raman light scattering study and microstructural analysis of epitaxial films of the electron-doped superconductor La_{2-x}Ce_{x}CuO_{4}