Publications de Vincenzo Savona

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Thermalization in quantum many-body systems typically unfolds over timescales governed by intrinsic relaxation mechanisms. Yet, its spatial aspect is less understood. We investigate this phenomenon in the nonequilibrium steady state (NESS) of a Bose-Hubbard chain subject to coherent driving and dissipation at its boundaries, a setup inspired by current designs in circuit quantum electrodynamics. The dynamical fingerprints of chaos in this NESS are probed using semiclassical out-of-time-order correlators wit

The initial dynamics of resonantly excited secondary emission from quantum wells are dominated by Rayleigh scattering due to excitons localized in the disordered quantum well potential. We show experimentally and theoretically how the temporal shape of the early response is related to details of the two-dimensional disorder potential, and we determine the mean amplitude of the fluctuations and the correlation length. Spectral interferometry performed with a. single speckle allows to investigate the phase of

Time-resolved measurements of the resonant Rayleigh scattering from quantum well excitons are shown to provide information on the energy-level statistics of the localized exciton states. The signal transients are reproduced by a microscopic quantum model of the exciton two-dimensional motion in presence of spatially correlated disorder. This model allows quantitative determination of the average energy separation between the localized states. Here this quantity turns out to be only a few times smaller than

We demonstrate that the control protocols of quantum information devices can be simulated by assuming a low-rank ansatz for the density matrix. The rationale underlying this assumption is that quantum information protocols, by design, operate in a regime of nearly pure quantum states. Within the low-rank assumption, the simulation of these protocols is considerably faster than solving the full Lindblad master equation. This advantage can be used to increase the accuracy of the simulation by avoiding uncontr

The simulation of many-body open quantum systems is key to solving numerous outstanding problems in physics, chemistry, material science, and in the development of quantum technologies. Near-term quantum computers may bring considerable advantage for the e ...

An iterative scheme based on the kernel polynomial method is devised for the efficient computation of the one-body density matrix of weakly interacting Bose gases within Bogoliubov theory. This scheme is used to analyze the coherence properties of disorder ...

We study theoretically superfluidity in a driven-dissipative Bose gas out of thermal equilibrium, and discuss the relation with conventional superfluids. We show how the superfluid behavior is characterized by a dramatic increase in the lifetime of a quant ...

Time resolved photoluminescence in semiconductor microcavities in the strong coupling regime both for non-resonant and resonant excitation is modeled by considering scattering of exciton polaritons by acoustic phonons. Rise time and decay time of the luminescence signal are studied as a function of temperature. The polariton bottleneck effect is put into evidence in model structures which are free of leaky modes. In realistic structures these modes are instead expected to play a dominant role in the relaxat

We present QuantumToolbox.jl, an open-source Julia package for simulating open quantum systems. Designed with a syntax familiar to users of QuTiP (Quantum Toolbox in Python), it harnesses Julia's high-performance ecosystem to deliver fast and scalable simulations. The package includes a suite of time-evolution solvers supporting distributed computing and GPU acceleration, enabling efficient simulation of large-scale quantum systems. We also show how QuantumToolbox.jl can integrate with automatic differentia

The interacting electron-hole system is investigated in the framework of non-equilibrium Green's functions. Using the Bethe-Salpeter equation in the ladder approximation we derive a set of equations for the polarization of the interacting electron and hole system. By solving these equations we reproduce the photoluminescence spectrum for a continuous wave excitation. Calculations are performed in the one-dimensional case using a contact potential for electron-hole interaction, which allows to perform most o

Encoding quantum information onto bosonic systems is a promising route to quantum error correc-tion. In a cat code, this encoding relies on the confinement of the dynamics of the system onto the two-dimensional manifold spanned by Schrodinger cats of oppos ...

Control of the wave function of confined microcavity polaritons is demonstrated experimentally and theoretically by means of tailored resonant optical excitation. Three dimensional confinement is achieved by etching mesas on top of the microcavity spacer l ...

The mean squared value of the photonic disorder is found to be reduced by a factor of 100 in a typical GaAs based microcavity when exposed to a circularly polarized continuous wave optical pump without any special spatial patterning. Resonant excitation of ...

The system of one or several quantum wells embedded in a planar semiconductor Fabry-Perot microcavity with distributed Bragg reflectors is studied in the framework of both a semiclassical and a full quantum theory. The results obtained with the two treatments are proved to be equivalent. Simple analytical expressions for the exciton-radiation mixed mode energies are obtained. In particular the model of two coupled harmonic oscillators for the dispersion is shown to hold in the whole range of coupling consta

We show theoretically that polariton pairs with a high degree of polarization entanglement can be produced through parametric scattering. In our proposed scheme, varying the polarizations of the two pumps, we have a complete control over the symmetries of the produced state (i.e. singlet or triplet output). Our microscopic model shows how a tomographic reconstruction, based on two-time correlation functions, can provide a quantitative assessment of the level of entanglement produced under realistic experime

We calculate scattering rates of QW excitons by acoustic phonons using realistic deformation potentials for electrons and holes in structures based on GaAs. We use these rates in order to reproduce the exciton dynamics in a time-resolved photoluminescence experiment. Rise time and decay time of the luminescence signal are studied as a function of temperature and QW size. The exciton distribution function reaches a stationary shape after the luminescence passes through its maximum. This shape shows strong de

We model the resonant excitation transfer between semiconductor quantum dots, accounting for the radiative nature of the electromagnetic field. The model based on Maxwell equations and on a non-local, and for linear susceptibility accounts both for the instantaneous dipole-dipole coupling, decaying as R-3 retardation effects, decaying as R-1. The coupling is strongly resonant and its spatial range is of the order of the wavelength, due to the radiative nature of the retarded contribution. (c) 2007 Elsevier

The third-order nonlinearity of silicon gives rise to a spontaneous four-wave mixing process in which correlated photon pairs are generated. Sources based on this effect can be used for quantum computation and cryptography, and can in principle be integrat ...

The Hartree-Fock-Popov theory of interacting Bose particles is developed, for modeling exciton-polaritons in semiconductor microcavities undergoing Bose-Einstein condensation. A self-consistent treatment of the linear exciton-photon coupling and of the exc ...

We propose a system of coupled microring resonators for the generation frequency combs and dissipative Kerr solitons in silicon at telecommunication frequencies. By taking advantage of structural slow-light, the effective non-linearity of the material is e ...

Vincenzo Savona

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Chaotic and quantum dynamics in driven-dissipative bosonic chains

Excitonic dephasing effects studied by time- and phase-resolved secondary emission

Optical signatures of energy-level statistics in a disordered quantum system

Low-rank optimal control of quantum devices

Low-Rank Variational Quantum Algorithm for the Dynamics of Open Quantum Systems

Superfluid–insulator transition in weakly interacting disordered Bose gases: a kernel polynomial approach

Superfluidity of a nonequilibrium Bose-Einstein condensate of polaritons

Time resolved photoluminescence from a semiconductor microcavity - Temperature dependence and role of leaky modes.

QuantumToolbox.jl: An efficient Julia framework for simulating open quantum systems

Photoluminescence spectra in semiconductor confined systems: Effects of Coulomb correlation

Critical Schrodinger Cat Qubit

Coherent optical control of the wave function of zero dimensional exciton polaritons

Optically Erasing Disorder in Semiconductor Microcavities with Dynamic Nuclear Polarization

Quantum-Well Excitons In Semiconductor Microcavities - Unified Treatment Of Weak And Strong-Coupling Regimes

Emergent entanglement of microcavity polariton pairs

Effect of the scattering by phonons on the temperature dependence of the free QW exciton radiative lifetimes.

Long-range radiative interaction between semiconductor quantum dots

A compact, integrated silicon device for the generation of spectrally filtered, pair-correlated photons

Spectrum and thermal fluctuations of a microcavity polariton Bose-Einstein condensate

Slow-light enhanced frequency combs and dissipative Kerr solitons in silicon coupled-ring microresonators in the telecom band