Condensed Matter Physics

The condensed matter group includes Professors E. Economou, N. Flytzanis, N. Papanicolaou, I. Perakis, G. C. Psaltakis, G. Tsironis, P. Tzanetakis, X. Zotos, postdoctoral fellows, graduate students, and visitors.

The condensed matter section of the Department of Physics focusses on both fundamental and applied research topics, of importance for present and future-day technologies. It strives to understand the physics behind such emerging technologies as the new generation of photonic, opto-electronic, and nanoscale devices. Such devices will enable a wide variety of new applications, based on the manipulation of the charge and spin degrees of freedom of different materials, and the fabrication of new nanostructures with novel optical and electronic properties.

The goal of this group is two-fold:

  • to describe, starting from basic principles, how complex and fundamental physical processes lead to the interesting equilibrium or non-equilibrium properties of advanced materials

  • to generate new ideas for designing novel materials with desirable and optimized properties.

The theoretical activities cover all major fields of modern condensed matter physics and quantum control of matter, including:

  • Studies of ground state, excited state, dynamical, transport, magnetic, and optical properties of novel materials

  • Semiconductor physics

  • Ultra-fast, collective, and many-body processes on the nanometer and femtosecond scale

  • Properties of photonic crystals and left-handed materials

  • Superconductor and Josephson junction physics

  • Non-linear and biological physics

The condensed matter physics group uses state of the art analytical and computational techniques of modern many body theory. Extensive computational work is performed by using standard computational techniques and by developing new computational procedures. Current research efforts include the study of:

  • Magnetic order in semiconductors, metals, and insulators

  • Role of many-body correlations under reduced dimensionality

  • Bose-Einstein condensation in atomic systems, solitary waves and vortex rings in trapped Bose-Einstein condensates

  • Structural and electronic properties of crystalline and amorphous semiconductors

  • Many-body correlations and collective phenomena in the very fast non-linear optical response of nanometer-sized condensed matter

  • High temperature superconductivity

  • Charge and spin density waves

  • Quantum transport and relaxation processes

  • Non-linear physical phenomena

  • Unconventional transport in quasi-one-dimensional materials

Work in the areas of non-linear and interdisciplinary physics includes the study of electronic and thermal properties of non-linear localized modes, fluxon dynamics in superconducting Josephson junctions, non-linear waves in molecular chains and surfaces with long range interactions, solitons, information transfer in optical fibers, computational modelling of complex phenomena, energy transfer properties of molecular crystals and biomolecules, protein motility, non-equilibrium properties of open systems, stochastic processes, and modelling of financial processes.

Research in semiconductor physics focusses, among others, on the structural and electronic properties of crystalline and amorphous semiconductors and their nanostructures, dynamical effects, order-disorder phenomena in alloys such as Si-Ge, the stability of superlattices and heterostructures, chemical ordering in alloys, statistical and thermodynamic approaches to problems of disorder in semiconductors. This work is performed using Monte Carlo and Molecular Dynamics simulation methods, in conjunction with classical empirical potentials and tight-binding Hamiltonians.

The theoretical work on the ultra-fast non-linear optical response of nanostructures focusses on describing the role of the Coulomb and spin exchange magnetic interactions in determining the non-equilibrium properties of matter during extremely short time scales. Such many-body effects occur during time intervals of the order of one hundredth of a billionth of a second and are observed in the laboratory by using extremely short state-of-the art laser pulses. They lead to loss of quantum coherence (dephasing) and relaxation. The physical systems of interest include semiconductor and metal nanostructures.

Research efforts in the field of photonic and phononic crystals aim at developing materials with novel properties. Applications of this work range from gigahertz antennas and mobile telephony to acoustics. An ongoing effort also focusses on the properties of left-handed photonic materials

The experimental group studies the properties of hydrogenated amorphous silicon and other systems. For example, it investigates light induced degradation by studying the strong pulsed laser illumination and recombination properties of the carriers. This work is performed in conjunction with the Institute of Electronic Structure and Laser (IESL) at FORTH. This group also performs development work on photovoltaic GaAs cells and systems in a specialized laboratory, the "Photovoltaic Park", established jointly with the Technological Education Institute of Crete.

University of Crete - Department of Physics - P.O Box 2208 - GR-71003 Heraklion, Greece
phone: +30 2810 394300 - fax: +30 2810 394301