Publications by Vincenzo Savona

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We develop a quantum mechanical model for the interaction of excitons in a microcavity embedded quantum well with a short resonant laser pulse. The model assumes full in-plane coherence. A Gaussian distribution of exciton slates is included in order to take into account the exciton inhomogeneous broadening. A coupling with a classical electromagnetic held provides the initial excitation pulse, and the time dependent emitted signal is calculated. Very good agreement with the recent results of time-resolved l

The quest for identification and understanding of fractional vorticity is a major subject of research in the quantum fluids domain, ranging from superconductors, superfluid Helium-3 to cold atoms. In a two-dimensional Bose degenerate gas with a spin degree ...

We analyze an open many-body system that is strongly coupled at its boundaries to interacting quantum baths. We show that the two-body interactions inside the baths induce emergent phenomena in the spin transport. The system and baths are modeled as indepe ...

We study Kerr frequency combs and dissipative Kerr solitons in silicon photonic crystal coupled-cavity waveguides (CCWs) with globally optimized dispersion at telecom wavelengths. The corresponding threshold for comb generation is found to explicitly depen ...

We present a comparison between the semiclassical and the full quantum descriptions of optical properties of quantum wells (QWs) in semiconductor microcavities. The semiclassical theory, which is based on a nonlocal treatment of the optical response of a single QW, allows one to calculate reflectivity, transmission, and absorption curves. The quantum theory, which is developed in a quasi-mode approach for the coupling of-the closed-cavity modes to the outside radiation continuum, provides a description of p

Topological insulators have attracted abundant attention for a variety of reasons-notably, the possibility for lossless energy transport through edge states "protected" against disorder. Topological effects such as the quantum Hall state can be induced thr ...

We analyze and compare the effect of fabrication disorder on the quality factor of six well-known high-index photonic crystal cavity designs. The theoretical quality factors for the different nominal structures span more than three orders of magnitude, ran ...

The theory of resonant Rayleigh scattering of light by excitons in a disordered quantum structure is presented. Disorder is modeled by a random Gauss distributed potential with finite correlation length in space. The time dependent scattered si,anal under pulsed excitation is studied by solving the Schrodinger equation for the exciton center-of-mass motion. The key quantity turns out to be the distribution of energy level distances weighted by the optical matrix elements. The limit of classical center-of-ma

We experimentally investigate the relaxation of spatially confined microcavity polaritons. We measure the time- and energy-resolved photoluminescence under resonant excitation and in the low-density regime. In this way, we have access to the time evolution ...

Time-resolved up-conversion measurements of secondary emission from multiple quantum wells under resonant femtosecond excitation are reported for GaAs multiple quantum wells with qualitatively different interface disorder. The transient resonant Rayleigh scattering presents very peculiar features such as a long-lived signal and a nonmonotonic behaviour, which cannot be explained by a classical model. A microscopic model is proposed, where the quantum mechanical equation for the microscopic polarization is s

We have performed spectral interferometry with Rayleigh scattered light coming from a single speckle and emitted after resonant creation of excitons in GaAs quantum wells:: The experiment confirms the coherence of the secondary emission at early times, regardless of sample:parameters. but underlines the stochastic nature of a single speckle. The scattered electric field is calculated, correctly accounting for the center-of-mass quantization in the disordered potential. We find that the amplitudes of the ele

Phase transitions to quantum condensed phases - such as Bose - Einstein condensation (BEC), superfluidity, and superconductivity - have long fascinated scientists, as they bring pure quantum effects to a macroscopic scale. BEC has, for example, famously be ...

A combined theoretical and experimental analysis of the resonant Rayleigh scattering by excitons in a disordered GaAs quantum well with monolayer islands is reported. Experimentally, the coherent resonant Rayleigh scattering is deduced by means of both statistical speckle analysis and passively stabilized spectral interferometry. Theoretically, the effect of disorder is modelled by solving the time-dependent Schrodinger equation for the exciton center-of-mass motion. The disorder potential used in the model

A quantum theory of quantum well polaritons in semiconductor microcavities is developed. The model takes into account the coupling between the exciton level and the structured continuum of electromagnetic modes relative to the particular geometry of the microcavity. A general equation for the polariton dispersion is obtained as a function of the cavity and exciton parameters. The equation is valid in both weak and strong coupling regimes and reproduces the existing measurements of microcavity polariton disp

We study the unconventional photon blockade, recently proposed for a coupled-cavity system, in the presence of input and output quantum fields. Mixing of the input or output channels still allows strong photon antibunching of the output field, but for opti ...

The most important features of the physics of microcavity-embedded quantum wells are reviewed, with particular attention to the optical properties of exciton polaritons. The strong coupling regime, in which a finite polariton mode splitting appears (also called Rabi splitting), is studied. The problem of including both homogeneous and inhomogeneous broadening effects is addressed. The effects of exciton-phonon interaction and the polariton homogeneous broadening are briefly discussed. The influence of the q

We develop a general quantum mechanical method to calculate the dispersion relations of polariton modes for a quantum well embedded in a semiconductor planar microcavity. The method is based on the properties of the Green's function;of the electromagnetic field in a one dimensional dielectric structure. By means of this approach it is possible to express the dispersion relations in a compact form once the eigenmodes of the electromagnetic field in the region where the quantum well is placed are known. We di

The effect of irregular hole shape on the spectrum and radiation losses of a photonic crystal waveguide is studied using Bloch-mode expansion. Deviations from a circular hole are characterized by a radius fluctuation amplitude and correlation angle. It is ...

Simulating the dynamics and the non-equilibrium steady state of an open quantum system are hard computational tasks on conventional computers. For the simulation of the time evolution, several efficient quantum algorithms have recently been developed. Howe ...

A theoretical model for the investigation of the dynamics of microcavity polaritons in the strong-coupling regime is proposed. The resulting photoluminescence dynamics at small angles is studied as a function of the angle of observation, the cavity detuning, the lattice, and the free-carrier temperature. For small detunings, the strong dispersion of the microcavity polaritons at small angles results in a bottleneck relaxation dynamics, similar to the bulk one. However, important differences, related to the

Vincenzo Savona

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Theory of time-resolved light emission from polaritons in a semiconductor microcavity under resonant excitation

Dissociation dynamics of singly charged vortices into half-quantum vortex pairs

Emergent transport in a many-body open system driven by interacting quantum baths

Slow-Light Frequency Combs and Dissipative Kerr Solitons in Coupled-Cavity Waveguides

Polaritons In High Reflectivity Microcavities - Semiclassical And Full Quantum Treatment Of Optical-Properties

Haldane quantum Hall effect for light in a dynamically modulated array of resonators

Statistics of the disorder-induced losses of high-Q photonic crystal cavities

Time-resolved Rayleigh scattering of excitons: Evidence for level repulsion in a disordered system

Enhancement of microcavity polariton relaxation under confinement

Resonant Rayleigh scattering on quantum well excitons: Theory and experiment

Interferometric analysis of resonant Rayleigh scattering from two-dimensional excitons

Bose-Einstein condensation of exciton polaritons

Determining the structure of semiconductor heterointerfaces by excitonic optical spectra

Theory of polariton photoluminescence in arbitrary semiconductor microcavity structures

Input-output theory of the unconventional photon blockade

Strong coupling of exciton-polaritons in semiconductor microcavities

Exact Quantum Calculation Of Polariton Dispersion In Semiconductor Microcavities

Effect of hole-shape irregularities on photonic crystal waveguides

A quantum algorithm for the direct estimation of the steady state of open quantum systems

Bottleneck effects in the relaxation and photoluminescence of microcavity polaritons