Results for "Messina Vincenzina"

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Efficient Kernel-based Subsequence Search for User Identification from Walking ActivityJun 11 2019This paper presents an efficient approach for subsequence search in data streams. The problem consists in identifying coherent repetitions of a given reference time-series, eventually multi-variate, within a longer data stream. Dynamic Time Warping (DTW) ... More
Electrostatics in soft matterNov 27 2008Recent progress in the understanding of the effect of electrostatics in soft matter is presented. A vast amount of materials contains ions ranging from the molecular scale (e.g., electrolyte) to the meso/macroscopic one (e.g., charged colloidal particles ... More
Image charges in spherical geometry: Application to colloidal systemsApr 25 2002Jun 13 2002The effects of image charges (i.e., induced surface charges of polarization) in spherical geometry and their implication for charged colloidal systems are investigated. We study analytically and exactly a single microion interacting with a dielectric ... More
Spherical Colloids: Effect of Discrete Macroion Charge Distribution and Counterion ValenceApr 04 2001Apr 22 2002We report the coupled effects of macroion charge discretization and counterion valence in the primitive model for spherical colloids. Instead of considering a uniformly charged surface, as it is traditionally done, we consider a more realistic situation ... More
SUSY contributions to the charge asymmetry in K^+- -> pi^+- l^+ l^- decaysFeb 25 2002We analyse the contributions to the charge asymmetry in $K^\pm\to\pi^\pm\ell^+\ell^-$ decays induced by gluino-exchange diagrams in the context of supersymmetric models with generic flavour couplings. We show that sizeable deviations with respect to the ... More
Macroion adsorption: The crucial role of excluded volume and coionsOct 17 2007The adsorption of charged colloids (macroions) onto an oppositely charged planar substrate is investigated theoretically. Taking properly into account the finite size of the macroions, unusual behaviors are reported. It is found that the role of the coions ... More
Latest Jet Results from TevatronMay 15 2006May 16 2006This contribution reports preliminary jet results in ppbar collisions at sqrt(s)=1.96 TeV from the CDF and D0 experiments. The jet inclusive cross section, measured using both the Midpoint and the K_T jet clustering algorithm, is compared to next-to-leading ... More
Evidence from stellar rotation for early disc dispersal owing to close companionsJun 13 2019Young low-mass stars of equal-mass exhibit a distribution of rotation periods. At the very early phases of stellar evolution, this distribution is set by the star-disc locking mechanism. The primordial disc lifetime and, consequently, the duration of ... More
Role of hydrogen on the generation and decay of point defects in amorphous silica exposed to UV laser radiationMar 05 2007This experimental PhD work deals with the generation and transformation processes of point defects induced by UV laser irradiation on amorphous silicon dioxide (silica). The investigation relies on several spectroscopic techniques used to probe the microscopic ... More
Evidence from stellar rotation for early disc dispersal owing to close companionsJun 13 2019Jun 21 2019Young low-mass stars of equal-mass exhibit a distribution of rotation periods. At the very early phases of stellar evolution, this distribution is set by the star-disc locking mechanism. The primordial disc lifetime and, consequently, the duration of ... More
Long-term magnetic activity in close binary systems. I. Patterns of color variationsDec 13 2007We present the results of a long-term photometric monitoring project carried out at Catania Astrophysical Observatory and aimed at studying magnetic activity in close binary systems. We present the complete observations dataset (38,000 photoelectric observations ... More
Behavior of rod-like polyelectrolytes near an oppositely charged surfaceAug 02 2005Oct 19 2005The behavior of highly charged short rod-like polyelectrolytes near oppositely charged planar surfaces is investigated by means of Monte Carlo simulations. A detailed microstructural study, including monomer and fluid charge distribution, and chain orientation, ... More
W + Jet Production at CDFOct 17 2006Oct 20 2006The cross section for the inclusive production of W bosons in association with jets in ppbar collisions at sqrt(s)=1.96 TeV using the Collider Detector at Fermilab (CDF II) is presented. The measurement is based on an integrated luminosity of 320pb^-1, ... More
A single atom-based generation of Bell states of two cavitiesMar 28 2002A new conditional scheme for generating Bell states of two spatially separated high-Q cavities is reported. Our method is based on the passage of one atom only through the two cavities. A distinctive feature of our treatment is that it incorporates from ... More
Behavior of block-polyampholytes near a charged surfaceAug 22 2006The behavior of polyampholytes near a charged planar surface is studied by means of Monte Carlo simulations. The investigated polyampholytes are overall electrically neutral and made up of oppositely charged units (called blocks) that are highly charged ... More
Adsorption of Oppositely Charged Polyelectrolytes onto a Charged RodJun 12 2003Jul 22 2003The adsorption of highly charged flexible polycations and polyanions on a charged cylindrical substrate is investigated by means of Monte Carlo (MC) simulations. A detailed structural study, including monomer and fluid charge distributions, is provided. ... More
Effect of Image Forces on Polyelectrolyte Adsorption at a Charged SurfaceJun 03 2004The adsorption of flexible and highly charged polyelectrolytes onto oppositely charged planar surfaces is investigated by means of Monte Carlo simulations. The effect of image forces stemming from the dielectric discontinuity at the substrate interface ... More
Polyelectrolyte Multilayering on a Charged Planar SurfaceMay 23 2003Oct 22 2003The adsorption of highly \textit{oppositely} charged flexible polyelectrolytes (PEs) on a charged planar substrate is investigated by means of Monte Carlo (MC) simulations. We study in detail the equilibrium structure of the first few PE layers. The influence ... More
Patterning molecular scale paramagnets at Au Surface: A root to Magneto-Molecular-ElectronicsAug 20 2004Sep 18 2004Few examples of the exploitation of molecular magnetic properties in molecular electronics are known to date. Here we propose the realization of Self assembled monolayers (SAM) of a particular stable organic radical. This radical is meant to be used as ... More
Unitary transfer of entanglement in multipartite two-level systemsJun 05 2012The dynamics of a system composed by two pairs of dipolarly coupled two-level atoms is exactly studied. We show that the initial entanglement stored in a couple of atoms not directly interacting is fully transferred to the other pair in a periodic way. ... More
On the estimation of the Lorenz curve under complex sampling designsDec 09 2018This paper focuses on the estimation of the concentration curve of a finite population, when data are collected according to a complex sampling design with different inclusion probabilities. A (design-based) Hajek type estimator for the Lorenz curve is ... More
Scattering-matrix approach to Casimir-Lifshitz force and heat transfer out of thermal equilibrium between arbitrary bodiesAug 23 2011Oct 04 2011We study the radiative heat transfer and the Casimir-Lifshitz force occurring between two bodies in a system out of thermal equilibrium. We consider bodies of arbitrary shape and dielectric properties, held at two different temperatures, and immersed ... More
Casimir-Lifshitz force out of thermal equilibrium and heat transfer between arbitrary bodiesDec 23 2010Aug 23 2011We study the Casimir-Lifshitz force and the radiative heat transfer occurring between two arbitrary bodies, each one held at a given temperature, surrounded by environmental radiation at a third temperature. The system, in stationary configuration out ... More
Fluctuations of the Casimir-Polder force between an atom and a conducting wallJun 12 2007We consider the quantum fluctuations of the Casimir-Polder force between a neutral atom and a perfectly conducting wall in the ground state of the system. In order to obtain the atom-wall force fluctuation we first define an operator directly associated ... More
Three-body radiative heat transfer and Casimir-Lifshitz force out of thermal equilibrium for arbitrary bodiesFeb 11 2014We study the Casimir-Lifshitz force and the radiative heat transfer in a system consisting of three bodies held at three independent temperatures and immersed in a thermal environment, the whole system being in a stationary configuration out of thermal ... More
Distilling angular momentum nonclassical states in trapped ionsMay 14 2004In the spirit of Quantum Non-Demolition Measurements, we show that exploiting suitable vibronic couplings and repeatedly measuring the atomic population of a confined ion, it is possible to distill center of mass vibrational states with well defined square ... More
N-qubit states as points on the Bloch sphereOct 04 2009Oct 01 2010We show how the Majorana representation can be used to express the pure states of an N-qubit system as points on the Bloch sphere. We compare this geometrical representation of N-qubit states with an alternative one, proposed recently by the present authors. ... More
Relaxation back to equilibrium after cessation of shear for confined colloidal bilayersJun 24 2005Crystalline bilayers of charged colloidal suspensions which are confined between two parallel plates and sheared via a relative motion of the two plates are studied by extensive Brownian dynamics computer simulations. The charge-stabilized suspension ... More
Polynomial method to study the entanglement of pure N-qubit statesAug 12 2009Jan 12 2010We present a mapping which associates pure N-qubit states with a polynomial. The roots of the polynomial characterize the state completely. Using the properties of the polynomial we construct a way to determine the separability and the number of unentangled ... More
Self-Assembly of Magnetic Spheres in Strong Homogeneous Magnetic FieldFeb 02 2016The self-assembly in two dimensions of spherical magnets in strong magnetic field is addressed theoretically. %% It is shown that the attraction and assembly of parallel magnetic chains is the result of a delicate interplay of dipole-dipole interactions ... More
Hydrogen-Related Conversion Processes of Ge-Related Point Defects in Silica Triggered by UV Laser IrradiationSep 28 2005The conversion processes of Ge-related point defects triggered in amorphous SiO2 by 4.7eV laser exposure were investigated. Our study has focused on the interplay between the (=Ge•-H) H(II) center and the twofold coordinated Ge defect (=Ge••). ... More
In situ observation of the generation and annealing kinetics of E' centers induced in amorphous SiO2 by 4.7eV laser irradiationOct 24 2004Feb 26 2005The kinetics of E' centers induced in silica by 4.7eV laser irradiation was investigated observing in situ their optical absorption band at 5.8 eV. After exposure the defects decay due to reaction with diffusing molecular hydrogen of radiolytic origin. ... More
Are 2D-LSTM really dead for offline text recognition?Nov 27 2018There is a recent trend in handwritten text recognition with deep neural networks to replace 2D recurrent layers with 1D, and in some cases even completely remove the recurrent layers, relying on simple feed-forward convolutional only architectures. The ... More
Genuine Tripartite Entanglement in a Spin-Star Network at Thermal EquilibriumOct 08 2010Apr 14 2011In a recent paper [M. Huber {\it et al}, Phys. Rev. Lett. {\bf 104}, 210501 (2010)] new criteria to find out the presence of multipartite entanglement have been given. We exploit these tools in order to study thermal entanglement in a spin-star network ... More
Parametrized-4.5PN TaylorF2 approximant(s) and tail effects to quartic nonlinear order from the effective one body formalismMar 23 2017Jun 05 2018By post-Newtonian (PN) expanding the well-known, factorized and resummed, effective-one-body energy flux for circularized binaries we show that: (i) because of the presence of the resummed tail factor, the 4.5PN-accurate tails-of-tails-of-tails contribution ... More
Nd:YAG laser induced E' centers probed by in situ absorption measurementsFeb 03 2005We investigated various types of commercial silica irradiated with a pulsed Nd:YAG laser radiation (4.66 eV), with exposure time ranging up to 10000 s. Transient E' centers were probed in situ by measuring the amplitude of the optical absorption band ... More
Stability and UV completion of the Standard ModelJul 31 2015The knowledge of the stability condition of the electroweak (EW) vacuum is of the greatest importance for our understanding of beyond Standard Model (BSM) physics. It is widely believed that new physics that lives at very high energy scales should have ... More
Character of the reaction between molecular hydrogen and silicon dangling bond in amorphous SiO_2Mar 02 2007The passivation by diffusing H2 of silicon dangling bond defects (E' centers, induced by laser irradiation in amorphous SiO_2 (silica), is investigated in situ at several temperatures. It is found that the reaction between E' center and H_2 requires an ... More
Stability, Higgs Boson Mass and New PhysicsJul 19 2013May 27 2014When the particle with mass $\sim 126$ GeV discovered at LHC is identified with the Higgs boson of the Standard Model, intriguing and challenging questions arise. Among them, the issue of the EW vacuum stability. We find that, despite claims to the contrary, ... More
Manifold Mixup improves text recognition with CTC lossMar 11 2019Modern handwritten text recognition techniques employ deep recurrent neural networks. The use of these techniques is especially efficient when a large amount of annotated data is available for parameter estimation. Data augmentation can be used to enhance ... More
Reentrant transitions in colloidal or dusty plasma bilayersFeb 18 2003Aug 08 2003The phase diagram of crystalline bilayers of particles interacting via a Yukawa potential is calculated for arbitrary screening lengths and particle densities. Staggered rectangular, square, rhombic and triangular structures are found to be stable including ... More
Reconstruction of Hamiltonians from given time evolutionsJun 27 2010Feb 27 2011In this paper we propose a systematic method to solve the inverse dynamical problem for a quantum system governed by the von Neumann equation: to find a class of Hamiltonians reproducing a prescribed time evolution of a pure or mixed state of the system. ... More
Casimir-Polder force density between an atom and a conducting wallNov 14 2006In this paper we calculate the Casimir-Polder force density (force per unit area acting on the elements of the surface) on a metallic plate placed in front of a neutral atom. To obtain the force density we use the quantum operator associated to the electromagnetic ... More
Unitary Representations of Quantum Superpositions of two Coherent States and beyondJun 11 2013Jun 12 2013The construction of a class of unitary operators generating linear superpositions of generalized coherent states from the ground state of a quantum harmonic oscillator is reported. Such a construction, based on the properties of a new ad hoc introduced ... More
Dynamical Behavior of a Squid Ring Coupled to a Quantized Electromagnetic FieldMar 26 2002In this paper we investigate the dynamical behavior of a SQUID ring coupled to a quantized single-mode electromagnetic field. We have calculated the eigenstates of the combined fully quantum mechanical SQUID-field system. Interesting phenomena occur when ... More
Quantum superpositions of clockwise and counterclockwise supercurrent states in the dynamics of a rf-SQUID exposed to a quantized electromagnetic fieldNov 11 2002Nov 15 2002The dynamical behavior of a superconducting quantum interference device (a rf-SQUID) irradiated by a single mode quantized electromagnetic field is theoretically investigated. Treating the SQUID as a flux qubit, we analyze the dynamics of the combined ... More
Dynamic Work Distribution for PM AlgorithmMay 25 2000Although poor for small dynamic scales, the Particle-Mesh (PM) model allows in astrophysics good insight for large dynamic scales at low computational cost. Furthermore, it is possible to employ a very high number of particles to get high mass resolution. ... More
Photochemical generation of E' centre from Si-H in amorphous SiO2 under pulsed ultraviolet laser radiationMar 02 2007In situ optical absorption spectroscopy was used to study the generation of E' centres in amorphous SiO_2 occurring by photo-induced breaking of Si-H groups under 4.7eV pulsed laser radiation. The dependence from laser intensity of the defect generation ... More
Graphene-based photovoltaic cells for near-field thermal energy conversionJul 05 2012Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. In far field, the efficiency of these systems is limited by the thermodynamic Schockley-Queisser limit corresponding ... More
Riccati equation-based generalization of Dawson's integral functionJun 15 2007A new generalization of Dawson's integral function based on the link between a Riccati nonlinear differential equation and a second-order ordinary differential equation is reported. The MacLaurin expansion of this generalized function is built up and ... More
Exact treatment of operator difference equations with nonconstant noncommutative coefficientsJun 26 2012Dec 11 2012In this paper we study in a Hilbert space a homogeneous linear second order difference equation with nonconstant and noncommuting operator coefficients. We build its exact resolutive formula consisting in the explicit non-iterative expression of a generic ... More
Ultrafast Large Angle Beamstrahlung MonitorMar 26 2017The analysis of beamstrahlung radiation, emitted from a beam of charged particles due to the electromagnetic interaction with a second beam of charged particles, provides a diagnostic tool that can be used to monitor beam-beam collisions in a $e^{+}e^{-}$ ... More
Entanglement swapping in a Franson interferometer setupJun 18 2007Oct 03 2007We propose a simple scheme to swap the non local correlations, characteristic of a Franson interferometric setup, between pairs of frequency entangled photons emitted by distinct non linear crystals in a parametric down conversion process. Our scheme ... More
Three-body amplification of photon heat tunnelingMay 09 2012Resonant tunneling of surface polaritons across a subwavelength vacuum gap between two polar or metallic bodies at different temperatures leads to an almost monochromatic heat transfer which can exceed by several orders of magnitude the far-field upper ... More
Monte Carlo simulation of abnormal grain growth in two dimensionsNov 29 2000Abnormal grain growth in the presence of second phase particles is investigated with the help of a two-dimensional Monte Carlo simulation. An aggregate of equiaxed grains is considered with constant grain boundary energy and mobility. The only driving ... More
Scan, Attend and Read: End-to-End Handwritten Paragraph Recognition with MDLSTM AttentionApr 12 2016Aug 23 2016We present an attention-based model for end-to-end handwriting recognition. Our system does not require any segmentation of the input paragraph. The model is inspired by the differentiable attention models presented recently for speech recognition, image ... More
Polyelectrolyte Multilayering on a Charged SphereDec 12 2002Jun 16 2003The adsorption of highly \textit{oppositely} charged flexible polyelectrolytes onto a charged spherical surface is investigated by means of Monte Carlo simulations in a fashion which resembles the layer-by-layer deposition technique introduced by Decher. ... More
Strong electrostatic interactions in spherical colloidal systemsJan 17 2001Apr 26 2001We investigate spherical macroions in the strong Coulomb coupling regime within the primitive model in salt-free environment. We first show that the ground state of an isolated colloid is naturally overcharged by simple electrostatic arguments illustrated ... More
Effect of colloidal charge discretization in the primitive modelJun 30 2000Dec 21 2000The effect of fixed discrete colloidal charges in the primitive model is investigated for spherical macroions. Instead of considering a central bare charge, as it is traditionally done, we distribute \textit{discrete} charges randomly on the sphere. We ... More
Strong Attraction between Charged Spheres due to Metastable Ionized StatesJun 30 2000Dec 04 2000We report a mechanism which can lead to long range attractions between like-charged spherical macroions, stemming from the existence of metastable ionized states. We show that the ground state of a single highly charged colloid plus a few excess counterions ... More
Geometric phase accumulation-based effects in the quantum dynamics of an anisotropically trapped ionSep 25 2004Mar 31 2005New physical effects in the dynamics of an ion confined in an anisotropic two-dimensional Paul trap are reported. The link between the occurrence of such manifestations and the accumulation of geometric phase stemming from the intrinsic or controlled ... More
Realization of a space reversal operatorMay 13 2002In this paper we propose the realization of a bosonic-fermionic interaction in the context of trapped ions whose effect upon the ion center of mass degrees of freedom is properly speaking a spatial inversion. The physical system and its features are accurately ... More
Quantum Zeno Subspaces induced by TemperatureJun 11 2011We discuss the partitioning of the Hilbert space of a quantum system induced by the interaction with another system at thermal equilibrium, showing that the higher the temperature the more effective is the formation of Zeno subspaces. We show that our ... More
Dissipation and entanglement dynamics for two interacting qubits coupled to independent reservoirsJun 30 2008We derive the master equation of a system of two coupled qubits by taking into account their interaction with two independent bosonic baths. Important features of the dynamics are brought to light, such as the structure of the stationary state at general ... More
Perturbative Treatment of the Evolution Operator Associated with Raman CouplingsMay 10 2006A novel perturbative treatment of the time evolution operator of a quantum system is applied to the model describing a Raman-driven trapped ion in order to obtain a suitable 'effective model'. It is shown that the associated effective Hamiltonian describes ... More
New exactly solvable relativistic models with anomalous interactionSep 30 2009May 06 2011A special class of Dirac-Pauli equations with time-like vector potentials of external field is investigated. A new exactly solvable relativistic model describing anomalous interaction of a neutral Dirac fermion with a cylindrically symmetric external ... More
PT-symmetric $\varphi^4$ theory in d=0 dimensionsJan 02 2015A detailed study of a PT-symmetric zero-dimensional quartic theory is presented and a comparison between the properties of this theory and those of a conventional quartic theory is given. It is shown that the PT-symmetric quartic theory evades the consequences ... More
A compared analysis of the susceptibility in the O(N) theoryApr 12 2013The longitudinal susceptibility $\chi_L$ of the O(N) theory in the broken phase is analyzed by means of three different approaches, namely the leading contribution of the 1/N expansion, the Functional Renormalization Group flow in the Local Potential ... More
KineCluE: a Kinetic Cluster Expansion code to compute transport coefficients beyond the dilute limitSep 14 2018This paper introduces the KineCluE code that implements the self-consistent mean-field theory for clusters of finite size. Transport coefficients are obtained as a sum over cluster contributions (in a cluster expansion formalism), each being individually ... More
Low Energy Antineutrino Detection Using Neutrino Capture on EC Decaying NucleiMar 06 2009In this paper we present a study of the interaction of low energy electron antineutrino on nuclei that undergo electron capture. We show that the two corresponding crossed reactions have a sizeable cross section and are both suitable for detection of ... More
Exact formulas for radiative heat transfer between planar bodies under arbitrary temperature profiles: modified asymptotics and sign-flip transitionsSep 01 2016Nov 29 2016We derive exact analytical formulas for the radiative heat transfer between parallel slabs separated by vacuum and subject to arbitrary temperature profiles. We show that, depending on the derivatives of the temperature at points close to the slab--vacuum ... More
Dynamics of an elementary quantum system in environments out of thermal equilibriumMay 30 2012Dec 07 2012We study the internal dynamics of an elementary quantum system placed close to a body held at a temperature different from that of the surrounding radiation. We derive general expressions for lifetime and density matrix valid for bodies of arbitrary geometry ... More
Dynamical Casimir-Polder force on a partially dressed atom near a conducting wallOct 29 2010Nov 12 2010We study the time evolution of the Casimir-Polder force acting on a neutral atom in front of a perfectly conducting plate, when the system starts its unitary evolution from a partially dressed state. We solve the Heisenberg equations for both atomic and ... More
Time-dependent Maxwell field operators and field energy density for an atom near a conducting wallMar 18 2009We consider the time evolution of the electric and magnetic field operators for a two-level atom, interacting with the electromagnetic field, placed near an infinite perfectly conducting wall. We solve iteratively the Heisenberg equations for the field ... More
Like-Charge Colloid-Polyelectrolyte ComplexationJan 28 2002We investigate the complexation of a highly charged sphere with a long flexible polyelectrolyte, \textit{both negatively charged} in salt free environment. Electroneutrality is insured by the presence of divalent counterions. Using molecular dynamics ... More
Ground state of two unlike charged colloids: An analogy with ionic bondingJun 30 2000Sep 12 2001In this letter, we study the ground state of two spherical macroions of identical radius, but asymmetric bare charge ((Q_{A}>Q_{B})). Electroneutrality of the system is insured by the presence of the surrounding divalent counterions. Using Molecular Dynamics ... More
Resonant transitions due to changing boundariesJan 10 2015Apr 19 2019The problem of a particle confined in a box with moving walls is studied, focusing on the case of small perturbations which do not alter the shape of the boundary (\lq pantography\rq). The presence of resonant transitions involving the natural transition ... More
An algebraic approach to the study of multipartite entanglementApr 10 2012Dec 11 2012A simple algebraic approach to the study of multipartite entanglement for pure states is introduced together with a class of suitable functionals able to detect entanglement. On this basis, some known results are reproduced. Indeed, by investigating the ... More
Coarse grained and fine dynamics in trapped ion Raman schemesOct 27 2003Nov 03 2003A novel result concerning Raman coupling schemes in the context of trapped ions is obtained. By means of an operator perturbative approach, it is shown that the complete time evolution of these systems (in the interaction picture) can be expressed, with ... More
Tripartite thermal correlations in an inhomogeneous spin-star systemSep 22 2010Oct 05 2010We exploit the tripartite negativity to study the thermal correlations in a tripartite system, that is the three outer spins interacting with the central one in a spin-star system. We analyze the dependence of such correlations on the homogeneity of the ... More
Measurement of the W + Jet Cross Section at CDFAug 10 2007A measurement of W->e nu + n-jet cross sections in ppbar collisions at sqrt(s)=1.96 TeV using the Collider Detector at Fermilab in Run II is presented. The measurement is based on an integrated luminosity of 320 pb-1, and includes events with jet multiplicity ... More
A criterion for entanglement in two two-level systemsJun 29 2007We prove a necessary and sufficient condition for the occurrence of entanglement in two two-level systems, simple enough to be of experimental interest. Our results are illustrated in the context of a spin star system analyzing the exact entanglement ... More
On the merit of a Central Limit Theorem-based approximation in statistical physicsNov 04 2011The applicability conditions of a recently reported Central Limit Theorem-based approximation method in statistical physics are investigated and rigorously determined. The failure of this method at low and intermediate temperature is proved as well as ... More
General solution of a second order non-homogenous linear difference equation with noncommutative coefficientsApr 17 2008The detailed construction of the general solution of a second order non-homogenous linear operatordifference equation is presented. The wide applicability of such an equation as well as the usefulness of its resolutive formula is shown by studying some ... More
Ordinary versus PT-symmetric $φ^3$ quantum field theoryJan 05 2012A quantum-mechanical theory is PT-symmetric if it is described by a Hamiltonian that commutes with PT, where the operator P performs space reflection and the operator T performs time reversal. A PT-symmetric Hamiltonian often has a parametric region of ... More
The lifetime of the electroweak vacuum and sensitivity to Planck scale physicsAug 22 2014If the Standard Model (SM) is valid up to extremely high energy scales, then the Higgs potential becomes unstable at approximately $10^{11}$ GeV. However, calculations of the lifetime of the SM vacuum have shown that it vastly exceeds the age of the Universe. ... More
Binary crystals in two-dimensional two-component Yukawa mixturesJan 09 2008The zero-temperature phase diagram of binary mixtures of particles interacting via a screened Coulomb pair potential is calculated as a function of composition and charge ratio. The potential energy obtained by a Lekner summation is minimized among a ... More
Adversarial Generation of Handwritten Text Images Conditioned on SequencesMar 01 2019State-of-the-art offline handwriting text recognition systems tend to use neural networks and therefore require a large amount of annotated data to be trained. In order to partially satisfy this requirement, we propose a system based on Generative Adversarial ... More
Thermally-activated non-local amplification in quantum energy transportMay 13 2015Nov 18 2015We study energy-transport efficiency in light-harvesting planar and 3D complexes of two-level atomic quantum systems, embedded in a common thermal blackbody radiation. We show that the collective non-local dissipation induced by the thermal bath plays ... More
Detection of Noble Gas Scintillation Light with Large Area Avalanche Photodiodes (LAAPDs)Dec 23 2004Large Area Avalanche Photodiodes (LAAPDs) were used for a series of systematic measurements of the scintillation light in Ar, Kr, and Xe gas. Absolute quantum efficiencies are derived. Values for Xe and Kr are consistent with those given by the manufacturer. ... More
Steering Distillation by "Pulsed" and "Continuous" MeasurementsApr 09 2004May 14 2004A new systematic strategy for steering the distillation process for a quantum system, that utilizes the so-called "pulsed" and "continuous" measurements on another quantum system in interaction with the former, is proposed. The distillation process characterized ... More
Coupling-assisted Landau-Majorana-Stuckelberg-Zener transition in two-interacting-qubit systemsDec 16 2018We analyse a system of two interacting spin-qubits subjected to a Landau-Majorana-Stuckelberg-Zener ramp. We show that a LMSZ transitions of the two spin-qubits are possible without an external transverse static field since its role is played by the coupling ... More
Exactly solvable time-dependent models of two interacting two-level systemsApr 15 2016Two coupled two-level systems placed under external time-dependent magnetic fields are modeled by a general Hamiltonian endowed with a symmetry that enables us to reduce the total dynamics into two independent two-dimensional sub-dynamics. Each of the ... More
Quantum Phase Transitions and Heat Capacity in a two-atoms Bose-Hubbard ModelJul 08 2011We show that a two-atoms Bose-Hubbard model exhibits three different phases in the behavior of thermal entanglement in its parameter space. These phases are demonstrated to be traceable back to the existence of quantum phase transitions in the same system. ... More
Density matrix operatorial solution of the non--Markovian Master Equation for Quantum Brownian MotionNov 29 2002An original method to exactly solve the non-Markovian Master Equation describing the interaction of a single harmonic oscillator with a quantum environment in the weak coupling limit is reported. By using a superoperatorial approach we succeed in deriving ... More
The rotating wave system-reservoir coupling: limitations and meaning in the non-Markovian regimeDec 02 2002This paper deals with the dissipative dynamics of a quantum harmonic oscillator interacting with a bosonic reservoir. The Master Equations based on the Rotating Wave and on the Feynman-Vernon system--reservoir couplings are compared highlighting differences ... More
Interaction of bimodal fields with few-level atoms in cavities and trapsJun 21 2002The spectacular experimental results of the last few years in cavity quantum electrodynamics and trapped ions research has led to very high level laboratory performances. Such a stimulating situation essentially stems from two decisive advancements. The ... More
Crystalline multilayers of the confined Yukawa systemNov 28 2008Mar 18 2009The phase diagram of Yukawa particles confined between two parallel hard walls is calculated at zero-temperature beyond the bilayer regime by lattice-sum-minimization. Tuning the screening, a rich phase behavior is found in the regime bounded by stable ... More
A possible time dependent generalization of the bipartite quantum marginal problemNov 05 2018In this work we study an inverse dynamical problem for a bipartite quantum system governed by the time local master equation: to find the class of generators which give rise to a certain time evolution with the constraint of fixed reduced states (marginals). ... More