RESEARCH INTERESTS
ELECTRONIC CORRELATION |
The many body problem is one of the most
important ones in physics, in particular, the electronic correlation
plays a significative role in many solid-state phenomena such as
superconductivity, charge density waves and spin density waves.
In this research project we afford different techniques to solve in an
exact (in certain limits) or approximate way the electronic correlation
problem within simple models.
|
ANISOTROPIC SUPERCONDUCTIVITY |
Nowadays, a great variety of
two-dimensional superconductors
where the pair wavefunction shows different symmetries, are known. In
the magnesium diboride, as well as in the conventional superconductors,
the pairs have total spin zero (singlet) and the spatial wavefunction
has spherical symmetry. On the other hand,
the experimental evidence suggests that in the strontium ruthenate the
pairs have total spin one (triplet) and then, the spatial wavefunction
should be
antisymmetrical and, in the simplest case, it should have p symmetry.
Moreover, experiments based on the Josephson effect have given strong
evidence that in the
ceramic high temperature superconductors, the pairs have d symmetry.
This scenario
has triggered the research of new models beyond BCS theory. In this
project
we study, from a theoretical point of view, models that allow the
understanding of the different symmetries of superconducting gaps
observed in Nature. |
STRUCTURAL AND ELECTRONIC PROPERTIES OF BIMETALLIC NANOCLUSTERS |
Bimetallic nanoclusters,
also known as nanoalloys, are characterized by the fact that their
chemical and physical properties can be regulated not only by
changing their size and atomic ordering, but also by changing their
composition. In particular, varying the structures and compositions of
certain nanoalloys it is possible to dramatically modify their
catalitic properties. Moreover, many bimetallic catalysts present a
better performance than the monometallic ones. These nanoalloys usually
present structures and properties different to those of the
corresponding pure elements, for example Fe and Ag are inmiscible in
bulk but they are easily mixed in clusters of few atoms. |