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Scientific Report 2007-2009
Condensed matter physics and biophysics
Condensed matter physics and biophysics
Condensed matter physics has a strong tradition in the Physics Department of La Sapienza.
More than 50 scientists, with permanent positions (assistant, associate and full professors) and
30 affiliated researchers (mostly CNR staff) actively investigate different properties of hard, soft
and bio matter, or export ideas developed in condensed matter to new frontiers. This group of
scientist collaborates with about 20 post-docs and 25 Ph.D students enrolled in the Ph.D. school
of the department.
Let me guide you, with the help of the map shown in Figure below, through the several research
lines which are particularly active at the present time within the Physics Department.
One of the excellences of
our Department is in statistical
mechanics and physics
of complex systems, a field
which has developed from
the ideas developed in the
study of critical phenomena
and self-similarty, back in
the seventies. The science
of complexity arises naturally
from statistical mechanics
after the fundamental
change of paradigm with
respect to the reductionist
scientific vision stimulated
by the critical phenomena
studies. At the equilibrium
point between order and disorder
one can observe fluctuations
at all scales and the
system cannot be described
any more with the usual formalism in which one tries to write simple equations for average quantities.
From this conceptual grain many new concepts have developed which produced a revolution
in our way of looking at nature and the offspring of these ideas are now blooming in the study of
the most challenging open problems in statistical mechanic: scaling laws, renormalization group,
fractal geometry, glassy and granular systems, complex liquids, colloids, high-T c superconductivity
and many others.
High T c superconductivity is actively studied theoretically and experimentally (see
C1,C2,C3,C4,C5,C6). Experimental studies focus on material aspects, on how it is possible to
optimize physical parameters by changing external conditions as the pressure, temperature and
magnetic field, in addition to the chemical pressure and atomic disorder to obtain new materials
with possibly better superconducting function (C4) and on the anomalous transport properties
which characterize high-T c materials even in in their normal state (C5). Experimentalists also
focus on the sub-THz, infrared and optical spectra of different oxide families, characterized by
strong electron-electron and electron- phonon interaction to understand the exotic properties of
these materials, which range from high-T c superconductivity to the formation of charge density
waves, from the appearance of pseudogaps at remarkably high T to Mott transitions (C6). Several
theoretical groups work on new superconducting materials, with different approaches. Under
investigation is the possibility that the superconductivity transition could share a Berezinsky-
Sapienza Università di Roma 47 Dipartimento di Fisica