Andrea Marini [Curriculum Vitae (pdf)]
Picture kindly taken
by my four-years old son,
Matteo
My major research interest is the application of Many-Body techniques to
Condensed matter physics and nanoscience.
In particular the description and prediction of the ground-state, electronic and
spectroscopic properties of solids and nanomaterials.
I am especially interested in studying
the fundamentals of many body perturbation theory and static as well as time-dependent Density Functional Theory
(DFT and TDDFT).
My current research topics are non-linear and ultra-fast electronic processes: second-harmonic generation, optical gain, optical switches and
real-time femtosecond dynamics.
I have been member of the Condensed Matter Theory Group of the Physics Department of the University of Rome Tor Vergata, and of the European Theoretical Spectroscopy Facility. My current address is
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Istituto di Struttura della Materia (ISM) |
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Highlights
- Real-time approach to the optical properties of solids and nanostructures: Time-dependent Bethe-Salpeter equation
- C. Attaccalite, M. Gruning, and A. Marini, Phys. Rev. B 84, 245110 (2011).
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Many-body effects are known to play a crucial role in the electronic and optical properties of solids and nano-structures. Nevertheless the majority of theoretical and numerical approaches able to capture the influence of Coulomb correlations are restricted to the linear response regime. In this work we introduce a novel approach based on a real-time solution of the electronic dynamics. The proposed approach reduces to the well-known Bethe-Salpeter equation in the linear limit regime and it makes possible, at the same time, to investigate correlation effects in nonlinear phenomena. We show the flexibility and numerical stability of the proposed approach by calculating the dielectric constants and the effect of a strong pulse excitation in bulk h-BN.
- Effect of the Quantum Zero-Point Atomic Motion on the Optical and Electronic Properties of Diamond and Trans-Polyacetylene
- E. Cannuccia, A. Marini, Phys. Rev. Lett. 107, 255501 (2011)
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The quantum zero-point motion of the carbon atoms is shown to induce strong effects on the optical and electronic properties of diamond and trans polayacetylene, a conjugated polymer. By using an Ab-Initio approach, we interpret the sub-gap states experimentally observed in diamond in terms of entangled electron-phonon states. These states also appear in trans polayacetylene causing the formation of strong structures in the band-structure that even call into question the accuracy of the band theory. This imposes a critical revision of the results obtained for carbon-based nano-structures by assuming the atoms frozen in their equilibrium positions. 
- Anomalous Aharonov-Bohm Gap Oscillations in Carbon Nanotubes
- D. Sangalli, A. Marini, Nano Letters 11, 4052 (2011)
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The gap oscillations caused by a magnetic flux penetrating a carbon nanotube represent one of the most spectacular observations of the AharonovÀBohm effect at the nanoscale. Our understanding of this effect is, however, based on the assumption that the electrons are strictly confined on the tube surface, on trajectories that are not modified by curvature effects. Using an ab initio approach based on density functional theory, we show that this assumption fails at the nanoscale inducing important corrections to the physics of the Aharo- novÀBohm effect. Curvature effects and electronic density that is spilled out of the nanotube surface are shown to break the periodicity of the gap oscillations. We predict the key phenom- enological features of this anomalous AharonovÀBohm effect in semiconductive and metallic tubes and the existence of a large metallic phase in the low flux regime of multiwalled nanotubes, also suggesting possible experiments to validate our results. 