IRRATIONAL BELIEFS, PERSONALITY DYSFUNCTION, AND NEGATIVE EMOTIONAL OUTCOMES

This study examined the associations between dimensions of personality dysfunction, irrational beliefs, and negative outcomes (depression, social anxiety, anger). Participants consisted of 560 adults. Irrationality partially mediated the association between negative affect and depression, negative affect and social anxiety, and the associations between antagonism and anger, and disinhibition and anger. Our results conform to predictions of cognitive models of disordered personality, except that we did not find strong support for a unique role for specific sub-types of irrational beliefs

Light matter interaction in mesoscopic systems

The study of light-matter interaction has led to many fundamental discoveries as well as to the development of new technology. In this thesis, we investigate the interaction between light and matter in different mesoscopic systems such us Fabry-Perot cavities with fixed and/or moving mirrors (optomechanical cavities) and superconducting circuits. In the context of optomechanical cavities, we isolate genuine quantum contributions of the interaction between an optical field and a mechanical mirror and study how to probe nonlinearities of the mechanical motion. We also investigate dynamical corrections, arising from an initial non-equilibrium configuration of the system, to the Casimir energy induced by the interaction between a quantum multimode field and the quantum fluctuations of the movable mirror. In a cavity scenario, we further consider such kind of dynamical corrections for the Casimir-Polder force between an excited atom and a perfectly conducting mirror, finding new features that can allow for an easier way to single-out the dynamical Casimir-Polder effect. In the context of superconducting circuits, we explore the light-matter interaction between microwave fields and artificial atoms in the ultrastrong coupling regime, where the system displays a high degree of entanglement. We show how to extract these (otherwise inaccessible) quantum correlations, and how such correlations can potentially be exploited as a resource for entanglement-based applications. In all these investigations we provide feasible experimental scenarios where such new effects can be probed.Open Acces

Nonequilibrium dressing in a cavity with a movable reflecting mirror

We consider a movable mirror coupled to a one-dimensional massless scalar field in a cavity. Both the field and the mirror's mechanical degrees of freedom are described quantum-mechanically, and they can interact each other via the radiation pressure operator. We investigate the dynamical evolution of mirror and field starting from a nonequilibrium initial state, and their local interaction which brings the system to a stationary configuration for long times. This allows us to study the time-dependent dressing process of the movable mirror interacting with the field, and its dynamics leading to a local equilibrium dressed configuration. Also, in order to explore the effect of the radiation pressure on both sides of the movable mirror, we generalize the effective field-mirror Hamiltonian and previous results to the case of two cavities sharing the same mobile boundary. This leads us to address, in the appropriate limit, the dynamical dressing problem of a single mobile wall, bounded by a harmonic potential, in the vacuum space.Comment: 10 pages, 4 figure

Probing anharmonicity of a quantum oscillator in an optomechanical cavity

We present a way of measuring with high precision the anharmonicity of a quantum oscillator coupled to an optical field via radiation pressure. Our protocol uses a sequence of pulsed interactions to perform a loop in the phase space of the mechanical oscillator, which is prepared in a thermal state. We show how the optical field acquires a phase depending on the anharmonicity. Remarkably, one only needs small initial cooling of the mechanical motion to probe even small anharmonicities. Finally, by applying tools from quantum estimation theory, we calculate the ultimate bound on the estimation precision posed by quantum mechanics and compare it with the precision obtainable with feasible measurements such as homodyne and heterodyne detection on the cavity field. In particular we demonstrate that homodyne detection is nearly optimal in the limit of a large number of photons of the field and we discuss the estimation precision of small anharmonicities in terms of its signal-to-noise ratio.Comment: 8 pages, 2 figures, RevTeX

Dynamical Casimir-Polder force between an excited atom and a conducting wall

We consider the dynamical atom-surface Casimir-Polder force in the nonequilibrium configuration of an atom near a perfectly conducting wall, initially prepared in an excited state with the field in its vacuum state. We evaluate the time-dependent Casimir-Polder force on the atom and find that it shows an oscillatory behavior from attractive to repulsive both in time and in space. We also investigate the asymptotic behavior in time of the dynamical force and of related local field quantities, showing that the static value of the force, as obtained by a time-independent approach, is recovered for times much longer than the time scale of the atomic self-dressing but shorter than the atomic decay time. We then discuss the evolution of global quantities such as atomic and field energies and their asymptotic behavior. We also compare our results for the dynamical force on the excited atom with analogous results recently obtained for an initially bare ground-state atom. We show that new relevant features are obtained in the case of an initially excited atom, for example, much larger values of the dynamical force with respect to the static one, allowing for an easier way to single out and observe the dynamical Casimir-Polder effect

Quantum and Classical Phases in Optomechanics

The control of quantum systems requires the ability to change and read-out the phase of a system. The non-commutativity of canonical conjugate operators can induce phases on quantum systems, which can be employed for implementing phase gates and for precision measurements. Here we study the phase acquired by a radiation field after its radiation pressure interaction with a mechanical oscillator, and compare the classical and quantum contributions. The classical description can reproduce the nonlinearity induced by the mechanical oscillator and the loss of correlations between mechanics and optical field at certain interaction times. Such features alone are therefore insufficient for probing the quantum nature of the interaction. Our results thus isolate genuine quantum contributions of the optomechanical interaction that could be probed in current experiments.Comment: 10 pages, 3 figure

La ironía femenina en un epistolario del siglo XIX. Salta, Argentina

A partir de conceptos procedentes de la Teoría de la Relevancia (Sperber y Wilson, 1994), se indaga en el registro escrito de un epistolario decimonónico, relevado en el Noroeste argentino, a fin de analizar las formas particulares que reviste la ironía femenina como estrategia utilizada para provocar en el destinatario determinados efectos de sentido. El corpus examinado consta de tres cartas seleccionadas de ese epistolario y escritas por una remitente salteña del estamento patricio, cuyos receptores, sus dos hijos varones, habían sido alejados del núcleo familiar a los efectos de que se bastaran a sí mismos y adquirieran habilidad para los negocios. Las misivas revelan que ellos, a su vez, no siempre respondieron a las requisitorias maternas. Paradoja, imagen y atenuación son los tres recursos que la ironía asume en el breve corpus seleccionado y que muestran la destreza de la autora para alcanzar su objetivo, sin que se advierta, al invocar preceptos consagrados socialmente: la sumisión a la autoridad materna, a las normas religiosas, en general, a las estrictas pautas vigentes en aquella sociedad noroccidental argentina del siglo XIX.From concepts coming from the Relevance Theory (Sperber and Wilson, 1994), this work considers the written register of a collection of letters from the 19th century, documented in north-west Argentina, in order to analyse the particular forms taken by the female irony as a strategy used to produce meaning effects. The corpus analysed is composed of three letters, selected from this collection, written by a lady from Salta belonging to the patrician class, whose addressees, her two sons, had been set apart from their family in order that they learn how to be self-sufficient and develop business abilities. The letters reveal that they did not always meet their mother's demands. Paradox, image and mitigation are the three resources that irony takes in the brief corpus selected and those show the author' s skill to reach the objective without being noticed, resorting to socially recognized precepts: subjection to maternal authority, to the religious norms, in general, to the strict rules in force in this north-west argentine society in the 19th century

Effect of boundaries on vacuum field fluctuations and radiation-mediated interactions between atoms

In this paper we discuss and review several aspects of the effect of boundary conditions and structured environments on dispersion and resonance interactions involving atoms or molecules, as well as on vacuum field fluctuations. We first consider the case of a perfect mirror, which is free to move around an equilibrium position and whose mechanical degrees of freedom are treated quantum mechanically. We investigate how the quantum fluctuations of the mirror's position affect vacuum field fluctuations for both a one-dimensional scalar and electromagnetic field, showing that the effect is particularly significant in the proximity of the moving mirror. This result can be also relevant for possible gravitational effects, since the field energy density couples to gravity. We stress that this interaction-induced modification of the vacuum field fluctuations can be probed through the Casimir-Polder interaction with a polarizable body, thus allowing to detect the effect of the mirror's quantum position fluctuations. We then consider the effect of an environment such as an isotropic photonic crystal or a metallic waveguide, on the resonance interaction between two entangled identical atoms, one excited and the other in the ground state. We discuss the strong dependence of the resonance interaction with the relative position of the atomic transition frequency with the gap of the photonic crystal in the former case, and with the cut-off frequency of waveguide in the latter.Comment: 8 pages, 2 figures, Proceedings of the Eighth International Workshop DICE 2016 Spacetime - Matter - Quantum Mechanic

Field observables near a fluctuating boundary

We review several aspects related to the confinement of a massless scalar field in a cavity with a movable conducting wall of finite mass, free to move around its equilibrium position to which it is bound by a harmonic potential, and whose mechanical degrees of freedom are described quantum mechanically. This system, for small displacements of the movable wall from its equilibrium position, can be described by an e↵ective interaction Hamiltonian between the field and the mirror, quadratic in the field operators and linear in the mirror operators. In the interacting, i.e. dressed, ground state, we first consider local field observables such as the field energy density: we evaluate changes of the field energy density in the cavity with the movable wall with respect to the case of a fixed wall, and corrections to the usual Casimir forces between the two walls. We then investigate the case of two one-dimensional cavities separated by a movable wall of finite mass, with two massless scalar fields defined in the two cavities. We show that in this case correlations between the squared fields in the two cavities exist, mediated by the movable wall, at variance with the fixed-wall case