Metal-insulator transitions are accompanied by huge resistivity changes, even over tens of
orders of magnitude, and are widely observed in condensed-matter systems. This article …

The last decade witnessed significant progress in angle-resolved photoemission
spectroscopy (ARPES) and its applications. Today, ARPES experiments with 2-meV energy …

Besides superconductivity, copper-oxide high-temperature superconductors are susceptible
to other types of ordering. We used scanning tunneling microscopy and resonant elastic x …

We present an experimental review of the nature of the pseudogap in the cuprate
superconductors. Evidence from various experimental techniques points to a common …

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 …

This article discusses fluctuating order in a quantum disordered phase proximate to a
quantum critical point, with particular emphasis on fluctuating stripe order. Optimal strategies …

The Fermi surface—the set of points in momentum space describing gapless electronic
excitations—is a central concept in the theory of metals. In this context, the normal …

Recent studies of the electromagnetic response of high-T c superconductors using terahertz,
infrared, and optical spectroscopies are reviewed. In combination these experimental …

We present tunneling spectroscopy of Bi 2 Sr 2 CaCu 2 O 8+ δ single crystals as a function
of oxygen doping and temperature. The doping dependence amounts essentially to an …

This is a revised version of the first edition published in 1991. At the same time, this is a
revised version of the Syokabo edition, which was written in Japanese and published in …