Two Dimensional Systems Physics And New Devices

Two-Dimensional Systems: Physics and New Devices

In the series of International Winter Schools on New Developments in Solid State Physics, the fourth one was devoted to the subject: "Two Dimensional Systems: Physics and Devices". For the second time the pro ceedings of one of these Winter Schools appear as a volume in the Springer Series in Solid-State Sciences (the earlier proceedings were published as Vol. 53). The school was held in the castle of MauterndorfjSalzburg (Austria) February 24-28, 1986. These proceedings contain contributions ba:sed on the thirty invited lectures. The school was attended by 179 registered participants (40% students), who came from western European countries, the United States of America, Japan, the People's Republic of China and Poland. As far as the subjects are conterned, several papers deal with the growth and characterization of heterostructures. Dynamical RHEED tech niques are described as a tool for in situ studies of MBE growth mech anisms. Various growth techniques, including MBE, MOMBE, MOCVD and modifications of these, are discussed. The limiting fa.ctors for the carrier mobilities and the inftuence of the spacer thickness in single het erostructures of GaAs/GaAIAs seem to be understood and are no longer a matter of controversy. In addition, the growth of two fascinating systems, Si/SiGe and Hg _ Cd Te/CdTe, is discussed in detail

Two-Dimensional Systems

Two-Dimensional Coulomb Liquids and Solids

This book is about quantum phenomena in two-dimensional (2D) electron systems with extremely strong internal interactions. The central objects of interest are Coulomb liquids, in which the average Coulomb interaction en ergy per electron is much higher than the mean kinetic energy, and Wigner solids. The main themes are quantum transport in two dimensions and the dynamics of highly correlated electrons in the regime of strong coupling with medium excitations. In typical solids, the mutual interaction energy of charge carriers is of the same order of magnitude as their kinetic energy, and the Fermi-liquid ap proach appears to be quite satisfactory. However, in 1970, a broad research began to investigate a remarkable model 2D electron system formed on the free surface of superfluid helium. In this system, complementary to the 2D electronic systems formed in semiconductor interface structures, the ratio of the mean Coulomb energy of electrons to their kinetic energy can reach ap proximately a hundred before it undergoes the Wigner solid (WS) transition. Under such conditions, the Fermi-liquid description is doubtful and one needs to introduce alternative treatments. Similar interface electron systems form on other cryogenic substrates like neon and solid hydrogen.