1.1. MODELING USING PHENOMENOLOGICAL THEORIES
Up to now Ginzburg-Landau theory remains a powerful method in study of fundamental physical properties of superconductors. This theory has been widely accepted as a successfully phenomenological model for a superconductor. Last year many classes of multiband and anisotropic superconductors such as cuprate compounds, borocarbides, MgB2 and FeAs based superconductors were discovered. Ginzburg-Landau theory was generalized for the case superconductors with many band and anisotropic superconductors. Unconventional order parameter symmetry (d-wave and p-wave symmetry) taken into account in investigations. Another phenomenological models related with invsetigations of vortex dynamics, AC susceptibility and magnetization in intermediate state of II type superconductors.
AU group has experience on simulation and modeling of two-band Ginzburg-Landau equations. There are close collaborations betweenBelgium, Ukrainian theoretical groups. At the moment, AU group to fulfill the development of a new calculations using anisotropic and many band Ginzburg-Landau equations. For the first two years, the research will concentrate on modeling and simulation of time-dependent Ginzburg-Landau equations for the application to transport and fluctuation phenomena in superconductors. TheAnkaragroup is currently working on this aspect. For the five years, the research progress will include application of obtained results to real objects. Development of vortex dynamics investigations, calculations of magnetic quantities and generalization of Ginzburg-Landau theory to the case of existence of superconductivity and magnetism (as in unconventional compounds) in the scope of this stage. Final stages of investigations are comparison of obtained results with experimental data and possible implementation will be considered.
For the realization of this topic, at least 5-6 researches are required.
1.2. MICROSCOPICAL THEORY OF SUPERCONDUCTIVITY AND AB INITIO CALCULATIONS
Microscopical origin of superconductivity remains one of the most interesting research areas in physics and stood as a major scientific mystery for a large part of effors of teoreticians. It is well known that Eliashberg theory and its weak coupling limit BCS theory is applicable to electron-phonon based superconductors. İt is well known that CuO and FeAs based superconductors are unconventional superconductors. These systems can be considered strong correlate electron systems (see 1.3). However generalized to the case electron-boson interaction Eliashberg (BCS) theory highly interesting for application to unconventional superconductors.
AU group has experience on analytical calculations of BCS and Eliashberg theories. At the moment, AU group to fulfill the development of a new calculations using anisotropic and many band Eliashberg equations. For the first two years, the research will concentrate on calculation of Eliashberg equations for the application to study doping and isotope effects in CuO and FeAs based superconductors. TheAnkaragroup is currently working on this aspect. For the five years, the research progress will include full numerical calculations in application to real objects. Ab initio simulations of electronic and phononic spectrum of superconducting compounds with further using in Eliashberg equations are planned. Inhomogeneous Coulomb interaction also will be included into calculations. Final stage of will be prediction of possible superconductivity in new compounds.
For the realization of this topic, at least 5 researches are required.
1.3. PEDAGOGICAL ASPECTS OF SUPERCONDUCTIVITY
Education of young scientist to modern methods of solid state physics seems very important for the realization of RoadMap. Overview of current topics in superconductivity, modern numerical and experimental methods and corresponding recent developments in these areas will be be subject of periodical schools on superconductivity in the USTAM. Organization of periodical Ankara seminars on Problems of Superconductivity also necessary.