RESEARCH

DEVICE MODELLING
Development of a classical drift diffusion, Monte Carlo and quantum simulators and their application to the modelling of silicon nano-devices with high-k gate staks. The devices of interest are likely to have both conventional and novel architectures, employing both and silicon, strained silicon and silicon-germanium channels.

SEMICLASSICAL CARRIER TRANSPORT
Development of a quantum-corrected algorithm, that allows the introduction of collisional broadening in semiclassical electron transport Monte Carlo simulations. A basic theoretical analysis of the electron-phonon scattering from a quantum point of view has been outlined and a modification to the traditional MC algorithm has been developed on the basis of the perturbation theory. Our algorithm allows for CB at each scattering event, depending onthe time interval between two successive phonon interactions. All the carrier distributions obtained with CB-MC simulations exhibit some important deviations from those obtained with traditional MC. The algorithm is suitable for application in MC simulations of realistic device models.

QUANTUM ELECTRONIC TRANSPORT
Simulation of coherent and dissipative transport in electronic devices. Simulation of transport using the Schrödinger equation and the Wigner function. Investigation of modifications on electronic dynamics inside mesoscopic systems. The results obtained show that the transport properties depend on the dimensions of the region inside which the coherence of the electronic ensemble is retained. The contacts are supposed to spoil such a coherence, therefore the interference processes between the carrier wavefunction and the internal potential profile can be affected by the proximity of the contacts. Another research field has been the development of a Monte Carlo algorithm to study the electron dynamics in homogeneous semiconductor with phonon interactions, within a fully quantum formulation.
Title of the PhD thesis: "Effect of contact proximity on quantum transport in mesoscopic semiconductor systems". Advisor: Prof. C.Jacoboni.

ATOMIC PHYSICS
Study of the light-condensed matter interaction. Theoretical study of light scattering from rare earth, with particular interest in dichroism and magnetic materials. Derivation of sum-rules for light scattering in fast-collision approximation, with angular resolution. Derivation of cross section for light scattering without fast-collision approximation, with angular resolution. The interference effects among the intermediate states are described as a function of the directions and polarizations of the incoming and outcoming beams. The special case where the emission is due to inner-shell recombination is considered. A variety of peculiar effects are discussed. The simplest cases are analytically examined showing the potential sensitivity of this technique to the electronic structure.
Title of the graduating thesis: "X-ray inelastic Raman scattering with angular resolution".
Advisor: Prof. C.M.Bertoni.

LIST OF PUBLICATIONS

1. G. Ferrari, G. Goldoni, A. Bertoni, G. Cuoghi and E. Molinari "Magnetic States in Prismatic Core Multishell Nanowires", Nano Lett. 9 1631 (2009).
2. G. Ferrari, A. Bertoni, G. Goldoni, E. Molinari, "Cylindrical Two-Dimensional Electron Gas in a Transverse Magnetic Field", Phys. Rev. B 78, 115326 (2008).
3. Giulio Ferrari, J.R. Watling, S. Roy, J.R. Barker, and A. Asenov, “Beyond SiO₂ technology: Simulation of the impact of high-k dielectrics on mobility”, J. of Non-Crystalline Solids, accepted to be published, (2006).
4. Giulio Ferrari, J.R. Watling, S. Roy, J.R. Barker, P. Zeitzoff, G. Bersuker, and A. Asenov, “Monte Carlo study of mobility in Si devices with HfO₂ based oxides”, Materials Science in Semiconductor Processing, accepted to be published, (2006).
5. E. Cancellieri, M. Rosini, A. Bertoni, Giulio Ferrari, and C. Jacoboni, “Conductance of Winding Wires”, J. Comput. Electr., accepted to be published, (2006).
6. Giulio Ferrari, A. Asenov, M. Nedjalkov, and C. Jacoboni, “Introducing energy broadening in semiclassical Monte Carlo simulations”, J. Comput. Electr., accepted to be published, (2006).
7. Giulio Ferrari, J. Watling, S. Roy, J. Barker, P. Zeitzoff, G. Bersuker, and A. Asenov, “On the Impact of High-k Gate Stacks on Mobility: A Monte Carlo Study Including Coupled SO Phonon-plasmon Scattering”, J. Comput. Electr., accepted to be published, (2006).
8. Giulio Ferrari, E. Cancellieri, P. Bordone, and C. Jacoboni, “Quantum Phonon-Limited High-Field Electron Transport in Semiconductors”, Nonequilibrium Carrier Dynamics in Semiconductors, Springer Proceedings in Physics Series 110 (2006).
9. Giulio Ferrari, P.Bordone, and C. Jacoboni, “Electron Dynamics Inside Short-Coherence Systems”, Phys. Lett. A 356, 371 (2006).
10. J. R. Barker, J. R. Watling, and Giulio Ferrari, “SO phonon scattering rates at the Si-HfO₂ interface in Si MOSFETs”, J. Phys: Conference Series 38, 184 (2006).
11. E. Cancellieri, P. Bordone, A. Bertoni, Giulio Ferrari, and C. Jacoboni, “Wigner Function for Identical Particles”, J. Comput. Electr. 3, 411 (2004).
12. F. Borgatti, G. Ghiringhelli, P. Ferriani, Giulio Ferrari, G. van der Laan, and C.M. Bertoni, “Sum rules for resonant inelastic x-ray scattering: explicit form and angular dependence in perpendicular geometry”, Phys. Rev. B 69, 134420 (2004).
13. P. Ferriani, C.M. Bertoni, and Giulio Ferrari, “Angle-resolved resonant inelastic x-ray scattering from transition-metal magnetic ions”, Phys. Rev. B 69, 104433 (2004).
14. Giulio Ferrari, N. Giacobbi, P. Bordone, A. Bertoni, and C. Jacoboni, “Influence of contacts on the electron transport dynamics inside a mesoscopic system”, Semiconductor Science Technology 19, S254 (2004).
15. A. Bertoni, P. Bordone, Giulio Ferrari, N. Giacobbi, and C. Jacoboni, “Proximity effect of the contacts on electron transport in mesoscopic devices”, J. Comput. Electr. 2, 137 (2003).
16. P. Ferriani, G. Ghiringhelli, Giulio Ferrari, C.M. Bertoni, A. Tagliaferri, L. Braicovich, and N.B. Brookes, “Resonant Inelastic X-Ray Scattering from Magnetic Systems: Mn in MnFe₂O₄”, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 200, 220 (2003)