paper

Enhanced superconducting gaps in the tri-layer high- $T_{c}$ cuprate Bi $_{2}$ Sr $_{2}$ Ca $_{2}$ Cu $_{3}$ O $_{10 + I^´}$

arXiv:0905.1223 · doi:10.1103/PhysRevLett.104.227001

Abstract

We have investigated the optimally doped tri-layer cuprate Bi $_{2}$ Sr $_{2}$ Ca $_{2}$ Cu $_{3}$ O $_{10 + I^´}$ (Bi2223) by angle-resolved photoemission spectroscopy, and observed energy bands and Fermi surfaces originated from the outer and inner CuO $_{2}$ planes (OP and IP) separately. The OP band is overdoped (hole density $\sim$ 0.26/Cu) with a large d-wave gap of $I^_{0}$ $\sim$ 43 meV while the IP is underdoped ( $\sim$ 0.06/Cu) with an even large gap of $I^_{0}$ $\sim$ 60 meV. We propose that the enhancement of the $I^_{0}$ of IP is due to the minimal influence of out-of-plane disorder and that the OP gap is then enhanced through interlayer coupling, most likely a proximity effect from the IP.

5 pages, 4 figures

Enhanced superconducting gaps in the tri-layer high-Tc​ cuprate Bi2​Sr2​Ca2​Cu3​O10+I^´​

Abstract

Enhanced superconducting gaps in the tri-layer high- $T_{c}$ cuprate Bi $_{2}$ Sr $_{2}$ Ca $_{2}$ Cu $_{3}$ O $_{10 + I^´}$