https://doi.org/10.1007/s100510070010
Evidence for the strain critical point in high Tc superconductors
1
Dipartimento di Fisica, Università di Roma "La Sapienza", 00185 Roma, Italy
2
Department of Physics, Notre Dame University, 46566 Indiana, USA
3
Dipartimento di Chimica, Università di Roma "La Sapienza", 00185 Roma, Italy
4
Istituto Strutturistica Chimica, Area della Ricerca, CNR, Monterotondo Stazione, Italy
5
Unità INFM and Dipartimento di Fisica, Università di Roma "La Sapienza",
00185 Roma, Italy
Corresponding author: a bianconi@superstripes.com
Received:
25
September
2000
Published online: 15 December 2000
We report experimental evidence for the phase diagram of doped cuprate superconductors as a function of the
micro-strain ε of the planar Cu-O bond length, measured by Cu K-edge EXAFS, and hole doping
δ. The local lattice distortions are measured by EXAFS and the charge ordering is measured by synchrotron
radiation diffuse X-ray diffraction. This phase diagram shows a QCP at P(
) where for
charge-orbital-spin stripes and free carriers co-exist. The superconducting phase
occurs in the region of critical fluctuations around this QCP. The function 
of two
variables shows its maximum at the strain QCP. The critical fluctuations near this strain QCP give the
self-organization of a metallic superlattice of quantum wires "superstripes" that favors the amplification of the
critical temperature.
PACS: 74.72.-h – High-Tc compounds / 61.10.-i – X-ray diffraction and scattering / 78.70.Dm – X-ray absorption spectra
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000
