Three-dimensional dispersion induced by extreme tensile strain in La_(2−x)Sr_xCuO_4 films
The electronic band structure probed by angle-resolved photoemission spectroscopy on thin epitaxial La_(2−x)Sr_(x)CuO_(4) films under extreme tensile strain shows anomalous features compatible with c-axis dispersion. This result is in striking contrast with the usual quasi-two-dimensional (2D) dispersion observed up to now in most superconducting cuprates, including relaxed and compressively strained La_(2−x)Sr_(x)CuO_(4) films grown under the same conditions. The data were analyzed using a 3D tight-binding dispersion for a body-centeredtetragonal lattice. We relate the enhancement of the c-axis dispersion to the significant displacement of the apical oxygen induced by epitaxial strain.
Institute of Physics of Complex Matter, EPFL, Switzerland and Synchrotron Radiation Center, University of Wisconsin, Madison.
Record created on 2007-02-12, modified on 2016-08-08