Almost fifty years after the paper "Introducing the Black Hole" by Ruffini and Wheeler and the Black Hole (BH) mass energy formula by Christodoulou Ruffini and Hawking, we can finally assert that we have been observing the moment of creation of a BH in the BdHN I GRB 190114C with corresponding rotational energy extraction process. The predicted properties of the BdHN I have been now observed:...
With accretion discs one can probe the strong gravity regime in the near vicinity of Black Holes. In this talk the general formalism for accretion disks in stationary axially symmetric Black Hole space-times is developed. In the case of matter models based on ideal fluids analytic solutions fort the density and pressure can be found. The formalism can be extended to charged fluids. In...
In this presentation we review some experimental and theoretical results obtained in our group related to laser ablation and laser patterning. The need of developing original solutions for obtaining nanostructured materials is raised. Furthermore we report on a new method that combines the Laser Ablation and the Sol-Gel techniques in order to obtain nanostructured glasses. Au nanoparticles are...
Time-reversal symmetry and its violation is one of the most powerful concepts in physics. It has applications in many physics subfields ranging from condensed matter, optics and atomic physics to mathematical physics and quantum field theories. In this talk, we will focus on two specific implementations of time-reversal symmetry (and its violation) in the field of electrodynamics with...
Photodetectors based on nanostructured semiconductor materials have been successfully used in advanced communications, flame detection, air purification, ozone sensing and leak detection, among others, in the past few decades. We present fabrication and characterization of photodetectors based on nanomaterials using their nanocolloids prepared by Liquid-phase Pulsed Laser Ablation technique...
The advent of gravitational wave astronomy has created opportunities to probe strong-field gravity as black holes merge. Numerical relativity provides the means to confront the measurements with theoretical prediction from general relativity, allowing us to interpret the sources of gravitational waves and to test whether general relativity is the theory governing these events. This talk will...
The diffraction of atomic and molecular beams is typically described by non-trivial solutions of the stationary Schroedinger equation. This has been done for structureless particles in the absence of external fields. In this contribution, the techniques that incorporate both internal composition and a gravitational field are presented. A derivation of the corresponding propagator is provided...
Nanoparticles (NPs) of Au and Ag were obtained by laser synthesis and processing of colloids, including laser ablation, fragmentation and melting in liquids. Some parameters as the laser pulse energy (from few mJ to100 mJ) and repetition rate of the laser pulses (RRLP, in the range from 1– 10 Hz), as well as the lens to target distance (LTD) were varied, which produced changes in the...
Materials that have properties of two-photon absorption (2PA), such as cyanine dyes, have wide applications in emerging areas such as coherent laser control, optical limiting, photofarmacology or 3-dimensional imaging of biological tissue [1,2]. In this study, the efficiency of 2PA of cyanines was explored by the two-photon induced fluorescence (TPIF) technique with a femtosecond laser [3]. An...
Nanostructures have an outstanding potential in several industrial applications, which has motivated to develop fast, easy and flexible methods for their fabrication. Laser irradiation of metal nanostructures such as thin films and nanoparticles induces melting and ablation, which allows the transformation of the nanostructures itself, and the structuration of the substrate below them. For...
I present the fundamentals of geometrothermodynamics (GTD), a formalism that represents in an invariant way thermodynamic laws and properties in terms of geometric concepts. The GTD of black holes is considered as a particular example and it is shown that a Legendre invariant metric, in which the mass, angular momentum and electric charge are considered as coordinates, can be used to describe...
We introduce an atomic gravimetric sequence using Raman-type composite light pulses that excites a superposition of two momentum states with the same internal level. The scheme allows the suppression of common noise, making it less sensitive to external fluctuations of electromagnetic fields. The Raman beams are generated with a fiber modulator and are capable of momentum transfer in opposite...
In this talk I address Regular Static Spherically Symmetric Black Holes (BH) constructed by introducing a de Sitter core, like the Hayward BH (HBH), then I compare the different trajectories in free fall, in the interior of the horizon, between a regular (HBH) and a singular (Reissner-Nordstrom) BH; the energy conditions are discussed as well as for the Regular Black Holes sourced by nonlinear...
Real-time and multi-elemental analysis for online water monitoring is an important task towards environmental safety, public health, water purification control, the adequate reuse of wastewater, and for many processes in engineering and industrial fields. However, the online water monitoring cannot be performed by analytical conventional techniques (LA-ICP-MS, ICP-OES or XRF) because they...
We propose in this letter a relativistic coordinate independent
interpretation for Milgrom's acceleration $a_{0}=1.2 \times 10^{-8}\hbox{cm/s}^{2}$ through a geometric constraint obtained from the product of the Kretschmann invariant scalar times the surface area of 2--spheres defined through suitable characteristic length scales for local and cosmic regimes, described by Schwarzschild and...
Ballistic electrons in phosphorene pn junctions show optical-like phenomena. Phosphorene is modeled by a tight-binding Hamiltonian that describes its electronic structure at low energies, where the electrons behave in the armchair direction as massive Dirac fermions and in the orthogonal zigzag direction as Schrödinger electrons. Applying the continuum approximation, we derive the electron...
Photocatalysis is an emerging field in which the solar energy/visible light is utilized for different types of catalytic applications including elimination of contaminants from water, air, soil, water splitting mechanisms, sterilization etc. Metal oxide nanoparticles and its different categories like modified metal oxides, nanocomposites, hybrids etc. were used commonly for photocatalytic...
A new general relativistic method for estimating the mass and spin parameters of a Kerr black hole (BH) from observational data is presented, i.e. from the red/blueshift of photons emitted by certain bodies orbiting around the BH, and the parameters characterizing their orbits (the radius and the polar angle for generic elliptical trajectories). With this method one can predict, and eventually...
In the last 20 years the field of nanotechnology has grown extensively due to its surface, optical and magnetic properties. Among the different types of nanoparticles gold nanoparticles (Au-NPs) outstand due its optical properties, chemical surface and biocompatibility. Laser ablation in liquids (LAL) is a synthesis method that allow to obtain high purity gold nanoparticles in a variety of...
We present theoretical and numerical results for the statistical averages of the scattered waves in disordered waveguides. The theoretical results, based on a perturbative method, show that the averages scattering amplitudes of the disordered region depend only on a few characteristic lengths related to microscopic details of the disorder: the mean free paths. Theoretical average amplitudes...
In arbitrary dimension, we consider a theory described by the most general quadratic curvature corrections of Einstein gravity together with a self-interacting nonminimally coupled scalar field. This theory is shown to admit five different families of Lifshitz black holes dressed with a nontrivial scalar field. The entropy of these configurations is microscopically computed by means of a...
The interest in Open Quantum Systems (OQS) has increased as OQS has been applied for the study of diverse physical phenomena. In this work we study the Wigner functions of the Harmonic Oscillator (HO) and two coupled Harmonic Oscillators (the Moshinsky atom). Both models were coupled with a bath under two different coupling bath-system regimes: a) pure-dephasing without relaxation and b)...
Three commercial brands of aluminum foil available in Mexico (Reinolds, Avilés, Great Value) are studied. In this work, we have obtained experimental results, which demonstrate that commercial aluminum foil enhances the Raman signal. The Raman signal enhancement of methylene blue at a concentration of 1x10-6 M has been analyzed by placing a drop (6 ul) onto samples of the three commercial...
In this work, a fast and efficient method for the synthesis of silver nanoparticles coated with silica by means of the laser ablation technique in combination with oxidation-reduction mechanisms in aqueous solution is presented. This method is a chemical synthesis where the reducer agent is introduced in nanometer form by laser ablation of a solid target submerged in an aqueous solution. In a...
We derive the electrically charged static black hole spacetime of the Einstein-Euler-Heisenberg theory, in terms of the Plebański dual variables. This solution is a non-linear electromagnetic generalization of the Reissner-Nordström solution and it is characterized by three parameters: mass M, electric charge Q_e , and Euler-Heisenberg non-linearity parameter A. We study the trajectories of...
The design of artificial materials, with emerging anomalous properties, is a very active frontier research today due to the multiple and novel applications based on new physics. These new materials, also called metamaterials, are characterized by their wave phenomenology that defies our intuition: superfocusing, invisibility and slowing down, among others.
The main challenge of...
In recent years, the use of thin films of metal chalcogenides has been increased in photovoltaic solar technology. Mainly, semiconductor materials such as Antimony Sulphide (Sb2S3) are used due to their high absorption coefficient and band gap (1.7-2.5 eV). However, Sb2S3 thin films obtained by chemical bath, the most common method of manufacturing them, have an absence of crystallinity,...
Irradiation with a single nanosecond laser pulse in the melting regime can result in a characteristic change in the surface morphology of crystalline silicon. This has been verified experimentally in a variety of situations. In certain irradiation conditions dimple-shaped surface topographies are produced. In this work the dimple height, depth and width are modelled following the approach of...
A way to construct a warped black hole in IIB supergravity will be presented. The two parameters that characterize the resulting solution are the size of the horizon and the warping factor. A D7-brane will be embedded in this background in such a way that a particular asymptotic behavior is achieved. Depending on the value of the parameters of the black hole, the embedding of the D7-brane can...
*sven.reichenberger@uni-due.de
The availability of laser-generated nanomaterials with gradually tuned intrinsic application-relevant properties (e.g. nanoparticle size, loading, alloy composition) and high purity allowed to systematically study and tailor materials for heterogenous catalysis, additive manufacturing and biotechnology in the recent decade. The scalable, surfactant-free...
This review describes the discovery of gravitational waves. We recount the journey of predicting and finding those waves, since its beginning in the early twentieth century, their prediction by Einstein in 1916, theoretical and experimental blunders, efforts towards their detection, and finally the subsequent successful discovery.
We show that it is possible emulate the pz orbitals of aromatic molecules using mechanical vibrations. This is done from the theoretical, numerical and experimental points of view. When connecting resonators through locally periodic structures, the resonances can be trapped thanks to the bandgaps of the locally periodic connectors [1,2]. This trapping yields a similar phenomenology to what...
Pulsed laser ablation in liquid (PLAL) is an interesting green technique to synthesize nanoparticles of metals, semiconductors, polymers and ceramics. We have synthesized nanoparticles of metals, semiconductors and ceramics using PLAL. Also explored the effects ablation wavelength, fluence and post irradiation effects on the morphology and properties of nanomaterials fabricated. From these...
The energy that carries an electromagnetic wave can be transferred to a chemical species via absorption. Once the molecule is in an excited state, it relaxes through various photophysical and photochemical channels [1]. Molecular dynamics is important because it involves the various deactivation channels through which the excitation energy dissipates. This study investigates the dynamics of...
We describe a particular excursion into the study of the localization phenomenon, kept within a family of simple model systems for the scattering of a propagating wave. The models are fully solvable and suitable for revealing an analogous nonlinear dynamical problem. A recursion relation for the system-size dependence of the scattering matrix relates to a bifurcation diagram where single point...
Detecting the electromagnetic (EM) counterpart of gravitational waves (GW) sources gives us with a wealth of information to understand the properties of the GW precursors. The fusion of neutron stars (NS) binaries has been identified as sources of GW. NS-NS fusions are also strong sources of EM radiation,they are called kilonovae. The light produced by kilonovae is mostly red, due to the...
CICESE was the first institution in México to build and operate (three decades ago) an ultrashort pulse laser system in México. In year 2003 we created the laboratory of ultrashort pulse lasers and processing of materials. Since then we have consolidated a research group that focuses on the following topics: fs laser-induced metallic oxides; fs laser-writing of photonics structures in...
While a longstanding subject in different areas of physics, quantum transport in “complex” systems has recently moved back into focus, not least due to remarkable progresses in the experimental characterization and control of multi-component quantum systems. Whereas quantum optics had long followed a strictly reductionist program, with the aim to isolate and control single constituents of...
I will speak about experiments with flat microwave resonators with and without induced time-reversal invariance violation. The scattering matrix formalism for such systems is equivalent to that developed for the random matrix theory description of compound nuclear reactions. Accordingly, the extraordinary advantage of such experiments is that they render possible the experimental verification...
Hypothetical ultralight bosonic particles have been suggested as (fuzzy) dark matter candidates. Such particles will spontaneously form macroscopic bosonic halos around spinning astrophysical black holes (BH), via an energy extraction process called superradiance, transferring part of the mass and angular momentum of the BH into the halo. I consider the phenomenology of this process, and of...
In the field of catalysis research and catalyst development especially tailored catalyst design is only possible when structure-activity correlations are mechanistically understood [1]. To that end, catalyst materials with gradually tuned properties are required. A promising tool to deliver nanomaterials with increasingly altered properties (e.g. band gap or photo-luminescence) and...
We will present a brief overview of CIO´s experimental work on ablation and micro-machining using an ultrafast amplified system (50 fs, 1 kHz). Specifically, we will cover surface nano- and micro-machining of stainless steel to achieve superhydrophobicity; also, we will present results on nanoparticle ablation from solid targets immersed in liquid.
One may think of classical stochastic processes as arising from the evolution of an open quantum system in the limit of strong decoherence. From this perspective, one would start with a quantum system, assume a coupling to the environment and eventually reach the classical stochastic process in the limit of strong decoherence. Here, we to proceed in the opposite direction: Given a...
If a black hole is seen against a backdrop of light sources, it shows a black disc known as the ``shadow'' of the black hole. In the first part of the talk I recall how the boundary curve of the shadow can be analytically calculated for an isolated (Schwarzschild or Kerr) black hole. Then I discuss how the cosmic expansion, in the simplest case just driven by a
cosmological constant, would...
The laser ablation of solids in liquid medium has been actively used in the last two decades for the synthesis and processing of nanoparticles. An important effect of the plasma formation as a result of the laser-solid interaction is that some of the plasma surrounding liquid is vaporized producing a cavitation bubble. This bubble expands to its maximum size and then collapses, this process...
Polymer quantum mechanics constitutes a theoretical lab where some of the mathematical techniques used in Loop Quantum Cosmology and Loop Quantum Gravity can be tested or better understood. On the other hand, the canonical transformations are an essential tool of the Hamiltonian formalism at both, classical and quantum level. In this talk, I will discuss the unitary representation of the...
We report results obtained in a laser-ablation experiment using targets chilled down to 20 K. In a previous work, our co-workers found that by increasing the temperature of the target above room temperature the emission of the lines increased in proportion to the target’s temperature [1]. In the present work we applied the focused beam of a pulsed, nanosecond Nd:YAG laser on a metallic surface...
The Earth's geoid is one of the most important fundamental concepts to provide a gravity field-related height reference in geodesy and associated sciences. To keep up with the ever-increasing experimental capabilities and to consistently interpret high-precision measurements without any doubt, a relativistic treatment of geodetic notions (including the geoid) within Einstein's theory of...
Silica aerogels are nanoporous lightweight materials the frame of which consists of an assembly of connected small cross-sections beam-like elements resulting from fused nanoparticles. This particular assembly additionally provides silica aerogel a very low elastic stiffness when compared to rigid silica structure of identical porosity. Therefore, when aerogel plates are clamped, they are...
Scalar Fields in the form of Bose-Einstein condensates (BEC's), seem to be a good candidate to describe dark matter in the universe. Even more, the existence of black holes in the center of some galaxies could be astrophysical phenomena that lead to the so-called quasi-bound states for the condensate that, in this scenario, can be interpreted as a galactic dark matter halo. By using the...
The plasma diagnostic is an in-situ method to monitor the deposition processes that involve the generation of plasmas. The pulsed laser ablation (PLA) and magnetron sputtering (MS) are plasma-assisted deposition techniques. Their combination is known as hybrid technique and denoted as MS-PLA. This hybrid technique has been employed to prepare coatings and films with specific applications such...
The proposal of loop (polymer) quantization of general relativity can be adapted to systems with finite number of degrees of freedom like each one of the infinite modes (harmonic oscillators) forming a scalar field to give rise to the Hosain-Husain-Seahra (HHS) model. This model crucially relies on the properties of the Mathieu solutions of the quantum pendulum that corresponds to the polymer...
A review of the tools taken from information theory and how they have been used to analyze quantum systems will be presented. Formulations of uncertainty relations in entropic terms will be discussed with emphasis on the behaviors in the position, momentum and phase-space representations. Statistical correlations between (among) particles will also be addressed
The unique properties of silver particles are strongly dependent on the size and shape of the nanoparticles, NPs [1]. Ablation synthesis in solution has some limitations in the size control of NPs. So, to have a uniform size distribution at the time of synthesizing the NPs in solution, either by chemical method [2] or by laser ablation [3], has been a problem that is difficult to solve. Among...
We consider a simple PT-symmetric tight-binding chain with gain and loss in a symmetric configuration. Using the explicit expressions for the eigenvalues and eigenvectors of the model, we obtain the values of the parameters at which exceptional points occur, and determine the behavior of the eigenvalues and eigenfunctions around these exceptional points perturbatively. These results are used...
In the last few years our group have been focusing on three main research areas. The first one concerns the study of cw-laser induced transformations in metal oxides and metals as molybdenum oxide and bismuth thin films. The second one is the study of pulsed ns-laser induced effects on some metallic materials as titanium, molybdenum and bismuth thin films, the third one and more recent is the...
In this talk we review some characteristics of the $\alpha$' corrections of black holes in the
context of Heterotic Superstring effective field theory. In particular we will discuss the corrections to non-extremal 4-dimensional dyonic Reissner-Nordström Black Holes. We argue that to first order in α', consistency with the equations of motion of the Heterotic Superstring demands additional...
In this work we present a new code to study perturbation theory in modified gravity. The code is based on the computation of the Lagrangian Perturbation Theory (LPT) kernels. From these kernel functions we can compute the correlation function in Convolution-LPT (CLPT) and the power spectrum in Standard Perturbation Theory (SPT). We applied the code to compute the correlation function in CLPT...
Time-driven quantum systems are essential in many different fields of physics as cold atoms, solid-state, optics, etc. Many of their properties are encoded in the time evolution operator or the effective Hamiltonian. Finding these operators usually requires very complicated calculations that often involve some approximations. In this talk, we present a theoretical model that exploits the...
We have observed anomalous conical emission from the first resonant transition of calcium (λca=422.67nm) using two types of laser beam, Gaussian and zeroth-order Bessel beams. We used the third harmonic of a Nd:YAG laser to pump a homemade tunable dye laser to excite the transition, and a 1° axicon to produce the Bessel beams. The conical emission featured different half-angles for the same...
One of the most fundamental predictions of general relativity are black holes. Their defining feature is the event horizon, the surface that even light cannot escape. When illuminated by ambient light, the event horizon of black holes will cast a dark shadow on the emitting region that is detectable under certain circumstances with global interferometers operating at mm- and submm-wavelengths....
In this talk we present the research studies at Escuela Superior de Física y Matemáticas-IPN and Facultad de Química-UAQ with the use of the Pulse Laser Deposition (PLD) technique. The research work is oriented to the following topics, namely: a) The thin film processing and characterization by PLD and applications as white light emitters of HfO2; b) Thin film processing and characterization...
We present a review of some important results obtained in the field of propagation and localization of waves in one-dimensional models with correlated disorder. In particular, we discuss how specific correlations of the random potential can give rise to peculiar transport properties in random media. We analyze some of the techniques used to deal with correlated disorder, including the...
Very soon the gravitational wave ground based detectors will hit the 50 binary Black Hole mergers detection milestone. This means that in less than five years, our knowledge about the existence of BHs have increased fivefold compared to what we have learned in the previous 40 years before the first gravitational wave detection.
What have we learned from gravitational wave astronomy about...
Cholesterol monolayers were deposited by the Langmuir-Blodgett (LB) technique on silicon wafers, glass slides, nano structured silicon wafers and nanostructured glass slides. These latter substrates are known as nanostructured substrates (SN) since they have deposited a silver film by the pulsed laser ablation technique (ALP). The films were characterized by the Raman spectroscopy technique to...
Two-dimensional (2D) van der Waals (vdW) heterostructures are a new realm of materials with potential applications and fascinating physical properties. Besides graphene (G), transition metal dichalcogenides (TMDCs) have been considered as promising building blocks in 2D vdW heterostructures with improved and new properties. The vertical stacking of at least two atomic monolayers bonded by vdW...
Lead-free piezoelectric materials were developed during the second half of the past century, among them, the potassium sodium niobate (K0.5Na0.5)NbO3 (KNN), KNN-based ferroelectrics and based ferroelectrics in Titanates of Barium (BaTiO3), are considered a promising lead-free materials alternative to Pb(Zr,Ti)O3 (PZT,) particularly the KNN by its high Curie temperature (Tc). Using PLD (pulsed...
Supermassive black holes with their extreme gravitational fields are at the forefront of research in extragalactic astrophysics. This talk outlines some of the major discoveries in black hole astrophysics, from early ideas to the most recent breakthroughs.
The laser induce periodic surface structures (LIPSS) have attracted considerable attention due to its potential to change, improve or provide new features to material surfaces. LIPSS appear as a quasi periodic pattern of parallel lines on the surface after being irradiated with linearly polarized laser radiation. These structures can be generated in a single-step process and their...
We consider the construction of a S0(4) scalar field theory non minimally coupled to a Couloumb potential. Using the symmetry we calculate the hydrogen atom spectrum. We find that the symmetry have among its generators a constant of motion that we can identify with a Relativistic Runge-Lenz vector.
In this talk we will present a brief historical review about metallic films with arrays of ordered holes which present extraordinary optical transmission. Then, the transmission properties of thin gold, copper and silver films deposited on quartz by pulsed laser deposition are presented. Well before the deposited metal forms a continuous film, these metals form islands on the substrate, when...
The Landauer-Büttiker formalism establishes an equivalence between the electrical conduction through a device, e.g., a quantum dot, and the transmission. Guided by this analogy we perform transmission measurements through three-port microwave graphs with orthogonal, unitary, and symplectic symmetry, thus mimicking three-terminal voltage drop devices. One of the ports is placed as input and a...
We use a classical optics approach to obtain the Bloch functions for several one-dimensional photonic crystals. To accomplish this, we choose the amplitude and phase representation, which leads us to a new procedure. These Bloch functions are based on numerical solutions to the field's amplitude equation, letting the refractive index vary continuously and periodically along one direction. Band...
I will first present a formalism to study symmetries in the context of diffeomorphism-invariant gauge theories. With it, I will show a universal symmetry algebra that contains the gauge symmetry and a covariant version of the diffeomorphisms. Then, I will include nondynamical fields that are supposed to describe effects associated with more fundamental degrees of freedom. Typically, these...
Currently there are a number of different methods for obtaining nanosized materials such as thermal oxidation, sol-gel method, solvothermal synthesis, among others. However, the laser ablation of solids in liquids (LASL) technique has acquired great importance due to its relatively low cost, also considered as a green technique because it does not generates by-products and extra chemicals are...
The common classification of the electronic phases (insulator, semiconductor, semimetal, and metal) of the matter is based on spectral properties. However, the discovery of the topological insulators (TI) added a new kind of classification based on topological information carried by the eigenstates of the system. A topological insulator is a material that behaves as an insulator in the bulk...
We review the idea of noncommutative smeared distributions of mass and charge as a tool for the construction of noncommutative inspired black holes. These solutions are free of singularities and possess interesting properties; using them, we discuss some of their applications in different physical scenarios.
The synthesis of molybdenum oxide (MoOx) nanoparticles (NPs) by using the laser ablation of solids in liquids (LASL) technique and their oxidation process was investigated. S/TEM-EDX microscopy images were used to study the oxidation process of these type of NPs. We hypothesized that the NPs oxidation depends on size, particularly it was observed that the smaller the NP not only the more...
We present a quantum framework for coarse graining and fuzzy measurements in a multiparticle system, based solely on what might be physically measured. For example the case of coarse graining, we assume that the detectors can measure only randomly selected particles with a physically motivated distribution. For the case of fuzzy measurements, we assume that the detectors might be placed...
We investigate a quantum geometric space in the context of what could be considered an emerging effective theory from quantum gravity. Specifically we consider a two-parameter class of twisted Poincaré algebras, from which Lie-algebraic noncommutativities of the translations are derived as well as associative star-products, deformed Riemannian geometries, Lie-algebraic twisted Minkowski...
In year 2004 we created the "Laboratorio de Fotomedicina, Biofotónica y Espectroscopía Láser de Pulsos Ultracortos". Since then we have consolidated the Laser Ablation of Solids in Liquids (LASL) technique through a 30 ps Nd:YAG laser system, UV-Vis spectroscopy and photoluminescence (PL) spectroscopy. Our research group focuses on the following topics: synthesis of colloidal nanoparticles by...
In this work we explore the possibility of a noncommutative origin to the cosmological constant. The results are derived in the context of noncommutative cosmology, where noncommutativity is introduced by a deformation on the minisuperspace variables. These ideas are explored in several examples, the main result is an effective cosmological constant in terms of the deformation parameters.
We present the entanglement measures of a tetrapartite W-Class entangled system in noninertial frame, where the transformation between Minkowski and Rindler coordinates is applied. Two cases are considered. First, when one qubit has uniform acceleration whilst the other three remain stationary. Second, when two qubits have nonuniform accelerations and the others stay inertial. The 1-1 tangle,...
Pulsed laser ablation in liquid technique is used frequently due to the advantage of obtention of stable, surfactant free nanomaterials in colloidal form. In this work, we synthesized semiconductor nanocolloids with laser ablation in liquid. The ablation process was carried out with pure Sb2S3 target and with additions of polycrystalline-Si and monocrystalline-Si in ethyl alcohol solution and...
Thin films of vanadium oxide compounded with silver were prepared by pulsed laser deposition using a two parallel plasmas and sequential plasmas configuration on glass and silicon substrates (100). These substrates were placed in front of the expansion line of the plasmas at a distance of 6 cm. For the array of parallel plasmas a high purity vanadium and silver targets were placed...
In this work the quantization of the superstring is performed via the deformation quantization formalism in the Neveu-Schwarz- Ramond approach. We use the Weyl-Wigner-Moyal-Groenewold formalism to carry out the quantization. The Stratonovich-Weyl operator, the Moyal star product and the Wigner function of the ground state for the superstring are obtained. The spectrum of states is also...
In this talk it is introduced the basics of Classical Plate Theory and Random Matrix Theory in order to appreciate the discovery and consequences of avoided crossings in a free vibrating rectangular elastic billiard. Mathematical, Numerical and Experimental evidences are presented.
In this work we present some results and analysis concerning the processing of semiconducting CdSe nanoparticles obtained by laser ablation of diluted CdSe powder in acetone. A Nd-YAG pulsed laser was used for ablation, tuned at the first and second harmonic, λ=1064 and 532 nm, 50 Hz frequency repetition during 30 minutes. The experiment was performed at different power intensities. An...
Uncertainty relations define one of the main differences between classical mechanics and quantum mechanics and are of fundamental importance in the description of quantum systems. In this talk the construction of uncertainty relations for systems with arbitrary phase spaces by means of deformation quantization formalism is discussed. In particular, the expressions of the so-called...
Quantum conductance in molecular and nano systems at low temperatures becomes well understood through the Landauer’s motto: “conductance is a transmittance” as calculated from the Schrödinger Equation (SE). However, quantum dynamics is inevitably affected by decoherence which, in turn, becomes critical to recover the macroscopic Ohm’s law. In spite of this, the few works that include these...
Pulsed laser deposition of thin films has proven to be a highly versatile technique for the growth of a number of different materials for almost any application. However, for the deposition of alloys, compounds or composite films, there are some drawbacks regarding targets preparation due to the deposited film is composed of two of more elements, making necessary the fabrication of targets...
Modeling black hole as punctures in space-time is common in binary black hole simulations. As the punctures approach each other, a common apparent horizon forms, signaling the coalescence of the black holes and the formation of the final black hole. In the first part of the talk, I will present results about the fate of the merging punctures inside the final black hole. While most studies of...
We will discuss the dynamics of quantum states in an energy transport model (photosynthesis) with a generator defined in terms of operators performing transitions between two mutually orthogonal subspaces, similar to birth and death transitions in classical stochastic processes or creation and annihilation operators in the quantum setting. It turns out that any stationary state has a portion...
In this work we report the synthesis of Graphite nanoparticles by laser ablation of a Graphite target immersed in distilled water. The laser used is a Nd: YAG emitting at 1064 nm with a pulsed length of 10 ns. The effect of an ultrasonic excitation and the laser energy density on the size and shape of the nanoparticles is investigated. The nanoparticles size and shape are determined from...
Material welding techniques have been a key aspect in the last industrial era. In fact, still there are some welding challenging applications that involve ceramic characteristics i. e. joining pieces of components in which biocompatibility or extremely high temperatures are in play. High temperature resistance of ceramics makes its welding a complex and difficult process.
The present work...
The theory of General relativity was postulated by Albert Einstein at the end of 1915. One of its main predictions was the existence of gravitational waves, that is perturbations of the geometry of space-time that travel at the speed of light, and are produced by violent astrophysical phenomena, sus as supernova explosions or the collisions of compact objects. However, gravitational waves are...
The supersymmetric formulation of quantum mechanics is a subject of intense activity in contemporary physics. It is addressed to analyze the spectral properties of exactly solvable potentials as well as to construct new integrable quantum models. In this talk we revisit the progress of such formulation since the introduction of the factorization method by Dirac to the construction of...
It has been demonstrated that carbon-based compounds, namely Expanded Graphite (EG), have become excellent fillers to reinforce polymers as Poly (ethylene terephthalate) (PET) to improve their mechanical resistance or electrical conductivity. Additionally, nanostructuring of polymers allows the modification of surface properties. A study about the generation of Laser Induced Periodic Surface...
Bimetallic nanoparticles have interesting properties for optical, electronic, magnetic and chemical applications. Pulsed laser ablation in liquid is an effective synthesis method to develop nanoparticles of metals, semiconductors and ceramics. In this work, colloidal solutions of bimetallic nanoparticles of silver / gold (50/50) were obtained by ablation using a Nd:YAG laser of 532 nm...
We describe the inverse method approach to determine parameters of astrophysical systems involving black holes. In the first case we review the reconstruction of binary black hole parameters out of the gravitational wave signal. In a second case we estimate parameters of a black hole out of the image observed, produced by matter around the black hole. In the two scenarios we describe the state...
Cooperative effects are at the center of interest in many systems in physics such as cold atomic clouds, light harvesting systems, and trapped ions. Cooperative effects such as Superradiance and Supertransfer induce enhanced energy transport efficiency and robustness to noise. In the first part of the talk we will review the role of Superradiance/Superabsorption in light-harvesting systems....
I will discuss some ideas about the interface between the quantum and gravitational realms, and the emergence of space-time itself, which led us to specific speculations about the way in which anticipated discrete aspects of quantum gravity might become manifest at the macroscopic level. We then will discuss an alternative description of gravitation, initially explored by Einstein, and known...
The laser ablation of solids in liquids (LASL) is a novel and growing route for the synthesis of nanomaterials. It is mainly based on two approximations: the laser ablation of solid targets and the laser fragmentation of suspended powders or micromaterials. In both, the laser, solvent and solid target and/or the suspended material can be tuned in order to reach the desired nanomaterials. In...
An analytic representation of the three-body potential for the ground state of the molecular ion $H^{++}_3$ in equilateral triangle configuration is presented. This representation is based on an adequate description of the two-body potential energy curve $V(R)$ for the diatomic molecule $H^+_2$. The accurate representation of $V(R)$ for $H^+_2$ is achieved by matching short and long distances...
Ultrafast laser inscription is a technique by which pulses from a femtosecond laser, are used to micro-structure the surface or the bulk of solid materials. One of the most interesting features of this kind of lasers is the high peak intensities that can be reached when the delivered pulses are tightly focused. The intensities are typically in the range of 1012 – 1015 W/cm2, which can easily...
The phrase “one measure for all men and all times” summarizes the ideal that would lead to the development of the International System of Units, SI. The evolution of the definitions of the SI units of measurement may be somehow considered as a series of approximations to such an ideal in which the units of measurement are invariant in time and space, immutable, and susceptible to equivalent...
