Local structure fluctuations as a signature of an inhomogeneous ground state in high-Tc superconductors.
In-plane polarized Cu K-edge XAFS on La2CuO4.1 is presented, which indicates a radial in-plane Cu-O distribution function that is not a single Gaussian. Fits to the isolated Cu-O XAFS signal show the presence of a two-site radial distribution function, similar to that found in other La-based cuprate superconductors at temperatures below the temperature associated with the pseudogap appearance, T*. The appearance of the two-site distribution is interpreted as evidence of a non-homogeneous ground state, preceding the superconducting transition. Similar results found in other copper-oxide superconductors indicate that this non-homogeneous ground state is a general feature of these materials.
Mustre de Leon
J
J
Departamento de Física Aplicada, Cinvestav-Mérida, Yucatán 97310, Mexico. mustre@mail.cinvestav.mx
Acosta-Alejandro
M
M
Conradson
S D
SD
Bishop
A R
AR