High temperature superconductivity in the cuprates: Materials, phenomena and a mechanism

Abstract

Superconductivity in the cuprates, discovered in the late 1980s and occurring at unprecedentedly high temperatures (up to about 140K) in about thirty chemically distinct families, continues to be a major problem in physics. In this article, after a brief introduction of these square planar materials with weak interlayer coupling, we mention some of the salient electronic properties of hole doped cuprates such as the pseudogap phase and the Fermi arc . We then outline a phenomenological, Ginzburg Landau like theory developed by some of us for the emergent d-wave symmetry superconductivity in these materials, and confronted successfully with a large amount of experimental information. A more recent application of the approach to fluctuation diamagnetism and to the anomalously large Nernst effect is also discussed.

Search for Novel Phases in Y-Ba-Cu-O Family

“…The probable reason is a very small fraction of the minor phases, which must be traced and recognized in the preparation methodology. The SC transition temperature of YBa 2 Cu 3 O 7−x decreases by removal of oxygen until, for x > 0.7, the material becomes an insulator indicated by the tetragonal crystal lattice, and the unit cell dimensions are a = b = 0.38570 nm and c = 1.18194 nm [6].…”