"Strong correlated electrons in semiconductors, metals and superconducting and magnetic materials. Subproject: strong correlated electrons and superconductivity in epitaxial cuprates thin films and junctions."

Supported by: Russian Academy of Sciences, Department of Physical Sciences, Project number
Duration: 2003 - 2005
Supervisor: Gennady Ovsyannikov, Dr. of Sci. in Physics., IREE RAS, Moscow, Russia

Summary

Bicrystal junction and heterostructures made of cuprate oxide material with strong correlated electrons will be investigated. Electrical and magnetic properties of these materials are rather far from those of Fermi liquid and remain poorly understood despite much theoretical and experimental works. The typical representative of cuprate oxide material YBa2Cu3Ox (YBCO) with d-symmetry wave superconducting wave function will be used.

The growth technical of epitaxial film by means of laser ablation and dc sputtering will be used for thin film fabrication. The structure and morphology of the film and heterostructure will be investigated by means of X-ray analysis and Atomic Force Microscope. DC, microwave and noise properties of the junction will be investigated.

Project objectives

To study the interplay of antiferromagnetism and superconductivity in dc conductivity and microwave resistance of perovskite-type cuprates oxides depending on doping in nanometer thin epitaxial films

To investigate anomalous proximity effect in heterosructure with antiferromagnetic depending on doping level and ferromagnetic interlayer

To study Andreev bound states and superconducting current transport in S/N/D heterostructure where S is metal-superconductor, N is normal metal, and D is oxide superconductor with d-wave symmetry. Subgap investigation in hybrid heterostructures.

To investigate noise spectral density in oxide superconducting bicrystal junction. To understand the role of Andreev bound states on the appearance of excess noise.

To develop new type of bicrystal junction with misorientation of c axes around the basic plane axes. To study quasiparticle and superconducting current transport in the structure.