The modelling and computational expertise that can be found in the Bologna unit reflects the different types of approach that are used to corroborate different activities that range from fundamental investigation of condensed matter to applicative researches related to sensors or devices design.
Seen from another perspective, one can find different steps of a so-called multiscale approach since our expertise ranges from atomistic simulation at the quantum level, to molecular dynamics up to continuum mechanics/finite element analysis for the description of the devices at the nano/micro-scale.
Parallel to these quantitative studies that aim at a realistic description of the materials under consideration we adopt also a modelistic point of view focusing on some relevant variables that characterise a complex system and building up efficient methods to solve the resulting equations of motions or Hamiltonians.
Typically this cannot be done fully at the analytical level so the different types of approach involve numerical solutions, provided either by commercial programs or by in-house/open source codes for which a methodological work of development and testing is also required.
In this spirit we list some of the most recent or most relevant lines of research in which we are involved:
Atomistic simulation of nanostructured graphene-based compounds
In order to assess the structural and electrical behaviour, especially in comparison to electron microscopy so to interpret and validate the response of this technique for samples with folded parts
- Dipartimento di Fisica, Università di Cagliari
Contact Person: C. Degli Esposti Boschi
Employed Software: Quantum Espresso suite
- L.Ortolani, E. Cadelano, G.P. Veronese, C.Degli Esposti Boschi, E. Snoeck, L. Colombo, V. Morandi, "Folded graphene membranes: Mapping curvature at the nanoscale", Nano Letters 12 5207 (2012)
- V. Morandi, L. Ortolani, A. Migliori, C. Degli Esposti Boschi, E. Cadelano, L. Colombo, "Folds and buckles at the nanoscale: Experimental and theoretical investigation of the bending properties of graphene membranes", Making and Exploiting Fullerenes, Graphene, and Carbon Nanotubes, 205 (2013)
Description of transport properties (charge & spin), decoherence and entanglement of quantum states
For lattice models of quantum devices or topological materials, typically with strongly correlations and low-dimensionality, by means of Density-matrix renormalisation group (DMRG) theory
- Dipartimento di Fisica e Astronomia dell'Università di Bologna
- Dipartimento Scienza Applicata e Tecnologia, Politecnico di Torino
Contact Person: C. Degli Esposti Boschi
- T. Roscilde, C. Degli Esposti Boschi, M. Dalmonte, "Pairing, crystallization and string correlations of mass-imbalanced atomic mixtures in one-dimensional optical lattices", EuroPhys. Lett. 97, 23002 (2012)
- C. Degli Esposti Boschi, E. Ercolessi, L. Ferrari, P. Naldesi, F. Ortolani, L. Taddia, "Bound states and expansion dynamics of interacting bosons on a one-dimensional lattice", Phys. Rev. A 90, 043606 (2014)
- C. Degli Esposti Boschi, A. Montorsi, M. Roncaglia, "Brane parity orders in the insulating state of Hubbard ladders", Phys. Rev. B 94, 085119 (2016)
Simulation of UV-Visible-NIR-MIR electromagnetic response of multilayer stacks of optical materials
Simulation of reflectance & transmittance spectra is capable of supplying information on an unexpected variety of experimental situations, thus proving to be a powerful, non destructive, non-contact rapid diagnostic technique for technological processes. The dispersion of optical constants can be determined both for isolated materials, and for materials inserted as a sub-component in a composite material and/or embedded in physical multilayer structure, as a component of an effective medium. Coherent and incoherent layers in any combination for any incidence angle are affordable using a Generalized Scattering Matrix Method.
Contact Person: C. Summonte (firstname.lastname@example.org)
- E.Centurioni, "Generalized matrix method for calculation of internal light energy flux in mixed coherent and incoherent multilayers", Applied Optics, 44, 7532 (2005)
- M. Allegrezza, F. Gaspari, M. Canino, M. Bellettato, A. Desalvo, C. Summonte, "Tail absorption in the determination of optical constants of silicon rich carbides", Thin Solid Films 556, 105 (2014); 564, 426 (2014 corrigendum)
Local Contact: C. Degli Esposti Boschi