High-pressure research in organic conductors

High-pressure studies on organic conductors and superconductors are reviewed. It is stressed that almost all the organic conductors are studied by means of high pressures, but the role or meaning of pressure effect has been dependent on the salts and physics of interests. In organic molecular crystals, many intriguing physical phenomena such as the appearance of charge- and spin-density-waves, superconductivity, Mott insulator and charge ordering have been found. The application of hydrostatic and uniaxial pressures plays an essential role for understanding the nature of these electronic states, for guiding the material design, and for creating the unexpected quantum states as well as high-T _c superconductivities. This review includes the history, pressure techniques, and works under conventional pressures of up to 1.5 GPa, ultra-high pressures up to 10 GPa as well as uniaxial pressure, but the topics which are dealt with in this same special issue are not covered.