Thursday, February 26, 2009

High-Tc Superconductors Are Very Kinky - Update 4

Another manuscript appears today addressing the high energy kinks found in the cuprate superconductors. This time, they compare the high energy kinks observed using ARPES between the electron-doped cuprates and the hole-doped cuprates[1].

Abstract: We have performed an angle-resolved photoemission spectroscopy (ARPES) study of Nd$_{1.85}$Ce$_{0.15}$CuO$_{4}$ (NCCO) in order to elucidate the origin of the high-energy kink (HEK) observed in the high-$T_{\rm c}$ superconductors (HTSCs). The energy scale of the HEK in NCCO is large compared with that in hole-doped HTSCs, consistent with previous ARPES studies. From measurement in a wide momentum region, we have demonstrated that between the hole- and electron-doped HTSCs the energy position of the HEK is shifted approximately by the amount of the chemical potential difference. Also, we have found that around $(\pi, 0)$ the HEK nearly coincides with the band bottom while around the node the band reaches the incoherent region and the HEK appears at the boundary between the coherent and incoherent regions.

Zz.

[1] M. Ikeda et al., http://arxiv.org/abs/0902.4280