Importance of structural instability to high-temperature superconductivity
Abstract
The orthorhombic-tetragonal structural phase transition of La2-xSrxCuO4 is quantitatively analyzed as a function of composition x within an anharmonic electron-phonon interaction model. The correct temperature dependence of the soft mode and the elastic constant c66 is obtained. The double-well potential in the electron-phonon interaction is derived self-consistently and found to vary strongly with x. In the vicinity of the superconducting transition temperature Tc electron-two-phonon interactions dominate the harmonic ones which may explain the high Tc's observed.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 1991
- DOI:
- Bibcode:
- 1991PhRvL..67..512B
- Keywords:
-
- Copper Oxides;
- Crystal Structure;
- Electron Phonon Interactions;
- High Temperature Superconductors;
- Phase Stability (Materials);
- Phase Transformations;
- Lanthanum Oxides;
- Strontium Compounds;
- Transition Temperature;
- Solid-State Physics;
- 74.20.-z;
- 63.20.Kr;
- 63.20.Ry;
- 77.80.-e;
- Theories and models of superconducting state;
- Phonon-electron and phonon-phonon interactions;
- Anharmonic lattice modes;
- Ferroelectricity and antiferroelectricity