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Evidence for forward scattering and coupling to acoustic phonon modes in high-T$_c$ cuprate superconductors

Authors :
Johnston, S.
Vishik, I. M.
Lee, W. S.
Schmitt, F.
Uchida, S.
Fujita, K.
Ishida, S.
Nagaosa, N.
Shen, Z. X.
Devereaux, T. P.
Source :
Phys. Rev. Lett. 108, 166404 (2012)
Publication Year :
2011

Abstract

Recent laser angle-resolved photoemission spectroscopy studies have established the presence of a new kink in the low-energy nodal dispersion of Bi$_2$Sr$_2$CaCu$_2$O$+{8+\delta}$ (Bi-2212). The energy scale (~8-15 meV) of this kink appears below the maximum of the superconducting gap $\delta_0$. Therefore it is difficult to interpret this feature in terms of the usual coupling to a sharp dispersionless mode. In this paper we examine electron-phonon coupling to the in-plane acoustic phonon branch arising from the modulation of the screened Coulomb potential. We demonstrate that such a coupling has a strong forward scattering peak, and as a consequence, a kink occurs in the dispersion at an energy scale shifted by the local gap $\delta(k)$. In addition, considerations for the reduction of screening with underdoping naturally explains the observed doping dependence of the low-energy kink. These results point to a strong coupling to the acoustic branch which is peaked in the forward scattering direction and has important implications for transport and pairing in the high-T$_c$ cuprates.<br />Comment: 4.5 pages, 4 figures, Submitted to PRL

Details

Database :
arXiv
Journal :
Phys. Rev. Lett. 108, 166404 (2012)
Publication Type :
Report
Accession number :
edsarx.1101.1302
Document Type :
Working Paper
Full Text :
https://doi.org/10.1103/PhysRevLett.108.166404