There is an enormous interest in renormalization of quasi-particle (qp) dispersion relation of cuprate superconductors both below and above the critical temperature Tc because it enables determination of the fluctuation spectrum to which the qps are coupled. A remarkable discovery by angle-resolved photoemission spectroscopy (ARPES) is a sharp low energy feature (LEF) in qp spectra well below the superconducting energy gap but with its energy increasing in proportion to Tc and its intensity increasing sharply below Tc. This unexpected feature needs to be reconciled with d-wave superconductivity. Here, we present a quantitative analysis of ARPES data from Bi2Sr2CaCu2O8+δ (Bi2212) using Eliashberg equations to show that the qp scattering rate due to the forward scattering impurities far from the Cu-O planes is modified by the energy gap below Tc and shows up as the LEF. This is also a necessary step to analyze ARPES data to reveal the spectrum of fluctuations promoting superconductivity.
@article{arxiv.1306.3731,
title = {Sharp low energy feature in single-particle spectra due to forward scattering in $d$-wave cuprate superconductors},
author = {Seung Hwan Hong and Jin Mo Bok and Wentao Zhang and Junfeng He and X. J. Zhou and Chandra M. Varma and Han-Yong Choi},
journal= {arXiv preprint arXiv:1306.3731},
year = {2014}
}
Comments
11 pages, 7 figure, 1 table, Accepted for publication in Phys Rev Lett, Includes the Supplemental Material