Mapping the Electronic Structure of Each Ingredient Oxide Layer of High-T_{c} Cuprate Superconductor Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} (original) (raw)

Physical review letters, 2015

Abstract

Understanding the mechanism of high transition temperature (T_{c}) superconductivity in cuprates has been hindered by the apparent complexity of their multilayered crystal structure. Using a cryogenic scanning tunneling microscopy (STM), we report on layer-by-layer probing of the electronic structures of all ingredient planes (BiO, SrO, CuO_{2}) of Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} superconductor prepared by argon-ion bombardment and annealing technique. We show that the well-known pseudogap (PG) feature observed by STM is inherently a property of the BiO planes and thus irrelevant directly to Cooper pairing. The SrO planes exhibit an unexpected van Hove singularity near the Fermi level, while the CuO_{2} planes are exclusively characterized by a smaller gap inside the PG. The small gap becomes invisible near T_{c}, which we identify as the superconducting gap. The above results constitute severe constraints on any microscopic model for high T_{c} superconductivity in cuprates.

Lili Wang hasn't uploaded this paper.

Let Lili know you want this paper to be uploaded.

Ask for this paper to be uploaded.