Theory of High Temperature Superconductivity

ISBN-13: 9781402001499 / Angielski / Twarda / 2001 / 374 str.

Shigeji Fujita;Fujita; S. Fujita

Opis

Flux quantization experiments indicate that the carriers, Cooper pairs (pairons), in the supercurrent have charge magnitude 2e, and that they move independently. Josephson interference in a Superconducting Quantum Int- ference Device (SQUID) shows that the centers of masses (CM) of pairons move as bosons with a linear dispersion relation. Based on this evidence we develop a theory of superconductivity in conventional and mate- als from a unified point of view. Following Bardeen, Cooper and Schrieffer (BCS) we regard the phonon exchange attraction as the cause of superc- ductivity. For cuprate superconductors, however, we take account of both optical- and acoustic-phonon exchange. BCS started with a Hamiltonian containing electron and hole kinetic energies and a pairing interaction with the phonon variables eliminated. These electrons and holes were introduced formally in terms of a free-electron model, which we consider unsatisfactory. We define electrons and holes in terms of the cur- tures of the Fermi surface. Electrons (1) and holes (2) are different and so they are assigned with different effective masses: Blatt, Schafroth and Butler proposed to explain superconductivity in terms of a Bose-Einstein Condensation (BEC) of electron pairs, each having mass M and a size. The system of free massive bosons, having a quadratic dispersion relation: and moving in three dimensions (3D) undergoes a BEC transition at where is the pair density."

Spis treści

1. Introduction. 2. Superconducting Transitions. 3. Bloch Electrons. 4. Phonon Exchange Attraction. 5. Quantum Statistical Theory. 6. Cooper Pairs (Pairons). 7. Superconductors at 0 K. 8. Quantum Statistics of Composites. 9. Bose-Einstein Condensation. 10. The Energy Gap Equations. 11. Pairon Energy Gaps and Heat Capacity. 12. Quantum Tunneling. 13. Flux Quantization. 14. Ginzburg-Landau Theory. 15. Josephson Effects. 16. Compound Superconductors. 17. Lattice Structures of Cuprates. 18. High-Tc Superconductors Below Tc. 19. Doping Dependence of Tc. 20. Transport Properties Above Tc. 21. Out-of-Plane Transport. 22. Seebeck Coefficient (Thermopower). 23. Magnetic Susceptibility. 24. Infrared Hall Effect. 25. d-Wave Cooper Pairs. 26. Connections with Other Theories. 27. Summary and Remarks. Appendix A. References. Bibliography. Index.