paper

Nanoscale interplay of strain and doping in a high-temperature superconductor

arXiv:1412.6088 · doi:10.1021/nl501890k

Abstract

The highest temperature superconductors are electronically inhomogeneous at the nanoscale, suggesting the existence of a local variable which could be harnessed to enhance the superconducting pairing. Here we report the relationship between local doping and local strain in the cuprate superconductor Bi $_{2}$ Sr $_{2}$ CaCu $_{2}$ O $_{8 + x}$ . We use scanning tunneling microscopy to discover that the crucial oxygen dopants are periodically distributed, in correlation with local strain. Our picoscale investigation of the intra-unit-cell positions of all oxygen dopants provides essential structural input for a complete microscopic theory.