Table of contents
About these proceedings
Advances in the physics and chemistry of low-dimensional systems have been really magnificent in the last few decades. Hundreds of quasi-one-dimensional and quasi-two-dimensional systems have been synthesized and studied. The most popular representatives of quasi-one-dimensional materials are polyacethylenes CH  and conducting donor-acceptor molecular crystals TIF z TCNQ. Examples of quasi-two-dimensional systems are high temperature su perconductors (HTSC) based on copper oxides LA2CU04, YBa2Cu306+y and organic superconductors based on BEDT -TIP molecules. The properties of such one- and two-dimensional materials are not yet fully understood. On the one hand, the equations of motion of one-dimensional sys tems are rather simple, which facilitates rigorous solutions of model problems. On the other hand, manifestations of various interactions in one-dimensional systems are rather peculiar. This refers, in particular, to electron--electron and electron-phonon interactions. Even within the limit of a weak coupling con stant electron--electron correlations produce an energy gap in the spectrum of one-dimensional metals implying a Mott transition from metal to semiconductor state. In all these cases perturbation theory is inapplicable. Which is one of the main difficulties on the way towards a comprehensive theory of quasi-one-dimensional systems. - This meeting held at the Institute for Theoretical Physics in Kiev May 15-18 1990 was devoted to related problems. The papers selected for this volume are grouped into three sections.
Magnetismus Optik Polyacethylen Polyacethylene Quantenkinetik Superconductivity Supraleitung high Tc hohe Tc magnetic field magnetische Eigenschaften molecule spectra