Professor Andrei Lebed
University of Arizona and Landau Institute

Novel Phases in Low-Dimensional Conductors and Superconductors

In the first part of our talk, we discuss a possibility of a novel super-crystalline phase to exist in quasi- one-dimensional conductor (Per)2Pt(mnt)2. This phase is characterized by periodically arranged soliton and anti-soliton walls with the period being a function of a magnetic field. We explain the existing experimental data and suggest new experiments to discover the super-crystalline phase in (Per)2Pt(mnt)2 and, possibly, in (Per)2Au(mnt)2.

In the second part of our talk, we argue that novel superconducting phase has to exist in a typical quasi-two-dimensional superconductors, including high-Tc and organic superconductors. This phase is called Reentrant Superconductivity and is characterized by paramagnetic Meissner effect, in contrast to the text book diamagnetic Meiisner effect. Paramagnetic Meissner currents are shown not to destroy superconductivity at high magnetic fields.