Novel Electronic Structure of Cuprate Superconductors Revealed by the Anomalous Spectral Lineshape in ARPES Experiments

Abstract

The fundamental questions raised by the anomalous spectral function seen in angle-resolved photoemission experiments (ARPES) have fascinated the community for ten years. The renormalization of energy scale from 8t (3 eV) to 2—3J (0.3 eV) appears to be understandable using the t—J model and its extensions and this success underscores the importance of the strong magnetic interaction and provides the basic Hamiltonian that can appropriately account for the local interactions. However, the path from the J scale local physics to the Tc (10 to 20 meV) scale long-range physics of superconductivity remains unclear. A revisit of the progress of the last decade and the unusual spectral lineshape that defy the understanding thus far suggest that the superconducting transition is not merely the opening of a gap due to an effective attractive interaction between well defined quasiparticles in the normal state but that these quasiparticles themselves are only formed upon lowering the temperature below Tc.