Although the vast majority of high-T c cuprate superconductors are hole-doped, a small
family of electron-doped compounds exists. Underinvestigated until recently, there has been …

Although nineteen years have passed since the discovery of high temperature cuprate
superconductivity, there is still no consensus on its physical origin. This is in large part …

The c axis reflectance of high-quality single crystals of YBa 2 Cu 3 O 6+ x has been
measured over a wide range of temperatures and frequencies. The x= 0.70 crystal has a …

The Van Hove singularity (VHS) provides a paradigm for the study of the role of peaks in the
density of states (dos) on electronic properties. More importantly, it appears to play a major …

We review the field of high temperature cuprate superconductors, with emphasis on the
nature of their electronic properties. After a general overview of experiment and theory, we …

The results of a systematic study of the optical properties of the YBa 2 Cu 3 O 6+ x-based
insulators and superconductors are reported. Specifically, we present measurements and …

We study the tJ and the Hubbard models at zero temperature using exact-diagonalization
techniques on√ 10×√ 10 and 4× 4 sites clusters. Quantum Monte Carlo simulation results …

We investigate the extended tJ model (which may include a small next-nearest-neighbor
antiferromagnetic coupling or a small hole-hole nearest-neighbor repulsion) by exact …

Transmission measurements have been performed in reduced SrTiO 3 between 300 and 17
K for different concentrations of oxygen vacancies. A midinfrared absorption band has been …

We have studied the development of the optical conductivity as electrons are added to the
Cu-O planes in Pr 2− x Ce x CuO 4− δ by varying x (0≤ x≤ 0.2). In the metallic phases …