An analysis of Helium resonant states in terms of entropy, information, complexity and entanglement measures

ABSTRACT: Shannon entropies and Fisher information calculated from one-particle density distributions and von Neumann and linear entropies (the latter two as a measure of entanglement) computed from the reduced oneparticle density matrix are analyzed for the 1,3Se,1,3 Po and 1,3De Rydberg series of He doubly excited states below the second ionization threshold. We find that both Fisher information and entanglement measures are able to discriminate resonances pertaining to different (K, T)A series

Information and entanglement measures applied to the analysis of complexity in doubly excited states of helium

ABSTRACT: Shannon entropy and Fisher information calculated from one-particle density distributions and von Neumann and linear entropies (the latter two as measures of entanglement) computed from the reduced one-particle density matrix are analyzed for the 1,3 Se, 1,3 Po, and 1,3 De Rydberg series of He doubly excited states below the second ionization threshold. In contrast with the Shannon entropy, we find that both the Fisher information and entanglement measures are able to discriminate low-energy resonances pertaining to different 2(K,T )An2 series according to the Herrick-Sinano˘glu-Lin classification. Contrary to bound states, which show a clear and unique asymptotic value for both Fisher information and entanglementmeasures in their Rydberg series 1sn for n→∞ (which implies a loss of spatial entanglement), the variety of behaviors and asymptotic values of entanglement above the noninteracting limit value in the Rydberg series of doubly excited states 2(K,T )A n2 indicates a signature of the intrinsic complexity and remnant entanglement in these high-lying resonances even with infinite excitation n2→∞, for which all known attempts of resonance classifications fail in helium

Función de Wigner y Decoherencia Cuántica para Sistemas Átomo-Campo en Cavidades QED

ABSTRACT: The processes of quantum decoherence in QED cavities have been extensively studied in the last decade, both experimentally by Haroche, Raimond et. al., as theoretically by Nemes, Davidovich et. to the. We present here the dynamics of the Wigner function for a system consisting of a two-level atom and a cavity in a dissipative environment, using a numerical integration scheme that allows us to consider initial Squeezed and Schrodinger's Cat States. The interaction between the atom and the single-mode field is considered by a dispersive model, that is, the interaction in the Hamiltonian of Jaynes-Cummings appears as a small disturbance. The interest is focused both on the quantum characteristics of the dispersive approach (preparation of mesoscopic states) and on the aspects that characterize dynamics and dissipation. In particular, the gradual loss of quantum coherence is observed through the use of the Wigner function, where the disappearance of the interference regions of the initial quantum states is evidenced.RESUMEN: Los procesos de decoherencia cuántica en cavidades QED han sido extensamente estudiados en la última década, tanto experimentalmente por Haroche, Raimond et. al., como teóricamente por Nemes, Davidovich et. al. Se presenta aquí la dinámica de la función de Wigner para un sistema conformado por un átomo de dos niveles y una cavidad en un ambiente disipativo, usando un esquema de integracion numérica que permite considerar estados iniciales tipo Squeezed y Schrodinger’s Cat States. La interacción entre el átomo y el campo monomodo se considera mediante un modelo dispersivo, es decir, la interacción en el Hamiltoniano de Jaynes-Cummings aparece como una pequeña perturbación. El interés se enfoca tanto en las características cuánticas de la aproximación dispersiva (preparación de estados mesoscópicos) como en los aspectos que caracterizan la dinámica y la disipación. En particular, se observa la pérdida gradual de las coherencias cuánticas mediante el uso de la función de Wigner, en donde se evidencia la desaparición de las regiones de interferencia de los estados cuánticos iniciales

The habitable zone of inhabited planets

ABSTRACT: In this paper we discuss and illustrate the hypothesis that life substantially alters the state of a planetary environment and therefore, modifies the limits of the HZ as estimated for an uninhabited planet. This hypothesis lead to the introduction of the Habitable Zone for Inhabited planets (hereafter InHZ), defined here as the region where the complex interaction between life and its abiotic environment is able to produce plausible equilibrium states with the necessary physical conditions for the existence and persistence of life itself. We support our hypothesis of an InHZ with three theoretical arguments, multiple evidences coming from observations of the Earth system, several conceptual experiments and illustrative numerical simulations. Conceptually the diference between the InHZ and the Abiotic HZ (AHZ) depends on unique and robust properties of life as an emergent physical phenomenon and not necesarily on the particular life forms bearing in the planet. Our aim here is to provide conceptual basis for the development of InHZ models incorporating consistently life-environment interactions. Although previous authors have explored the effects of life on habitability there is a gap in research developing the reasons why life should be systematically included at determining the HZ limits. We do not provide here definitive limits to the InHZ but we show through simple numerical models (as a parable of an inhabited planet) how the limits of the AHZ could be modified by including plausible interactions between biota and its environment. These examples aim also at posing the question that if limits of the HZ could be modified by the presence of life in those simple dynamical systems how will those limits change if life is included in established models of the AHZ

Impacto del acoplamiento luz-materia en las correlaciones a lo largo de la frontera clásico-cuántica en electrodinámica cuántica

ilustraciones, diagramasThis thesis commences with a comprehensive introduction, paving the way for the subsequent adaptation of four articles. Following this adaptation, the analysis narrows its focus to delve into the nuances of each article. In this analysis, we have explored various interrelated aspects of light-matter interactions in quantum systems, focusing on the role of different quasiparticle representations, the quantum dynamics of emitter assemblies within cavities, the phase transition from coherent to quantum-correlated phases, and the polariton vortices dynamics using a completely quantum approach. Our findings have provided valuable insights into the behavior of these complex quantum systems, as well as their potential applications and future research directions. The comparative analysis of quasiparticle representations in a two-quantum dotmicrocavity system has underlined the importance of selecting an appropriate basis to capture the system’s essential features and quasiparticle behavior effectively. We found that the polariton basis, consisting of dressed states of photons and excitons, can capture the underlying physics in various regimes of our model. Understanding the relationship between different bases and their ability to describe the system allows for a more accurate interpretation of the underlying physical processes, which is crucial for the design and implementation of quantum systems and devices. This understanding proved essential when analyzing the quantum dynamics of an assembly of emitters embedded within a cavity. We demonstrated that the efficient transfer of a threefold star light quantum state into the assembly of emitters is achievable only within the limit of a large number of emitters. This finding highlights the critical role of scalability in successfully manipulating quantum states and designing and optimizing experiments involving such systems. Moreover, our study revealed that the dressed states of photons and matter become independent of the number of two-level atoms in the assembly as the number of emitters increases, which is characterized by the cyclic appearance of antibunching and superbunching regimes. The insights gained from exploring the phase transition from coherent to quantumcorrelated phases in light-matter interactions have enabled us better to understand the interplay between quasiparticles and their coupling strengths. We identified that the assembly of emitters reaches coherence slightly before the photonic field, highlighting the subtle interplay between light and matter subsystems. Our findings have also revealed the critical role of quantum correlations in determining the system’s overall behavior, emphasizing the importance of studying entanglement properties across different regimes. Lastly, our investigation of polariton vortices dynamics using a completely quantum approach has shown that quantum superposition between light and matter leads to a more prosperous trajectory of the vortex core. Quantum exchange coupling results in interference effects on the trajectories of the vortex cores in both components, with more complex structures serving as solid evidence of quantum entanglement between the polariton components. (Texto tomado de la fuente)Esta tesis comienza con una introducción exhaustiva, allanando el camino para la posterior adaptación de cuatro artículos. Tras esta adaptación, el análisis estrecha su enfoque para profundizar en los matices de cada artículo. En este análisis, hemos explorado varios aspectos interrelacionados de la interacción entre luz y materia en sistemas cuánticos. Centrándonos en el papel de las diferentes representaciones de cuasipartículas, la dinámica cuántica de conjuntos de emisores dentro de cavidades, la transición de fase de estados coherentes a estados cuánticoscorrelacionados, y finalmente, la dinámica de vórtices polaritónicos utilizando un enfoque completamente cuántico. Nuestros hallazgos han proporcionado valiosos conocimientos sobre el comportamiento de estos sistemas cuánticos complejos, así como sus posibles aplicaciones y direcciones futuras en investigación. Iniciamos con el análisis comparativo de las representaciones de cuasipartículas en un sistema conformado por dos puntos cuánticos inmersos en una cavidad. Este muestra la importancia de seleccionar una base adecuada para capturar de manera efectiva las características esenciales del sistema y el comportamiento de las cuasipartículas. En esta contribución descubrimos que la base de polaritones, compuesta por estados vestidos de fotones y excitones, puede capturar la física subyacente en varios regímenes de nuestro modelo. Comprender la relación entre las diferentes bases y su capacidad para describir el sistema permite una interpretación más precisa de los procesos físicos subyacentes, lo cual es crucial para el diseño e implementación de sistemas y dispositivos cuánticos. Esta comprensión resultó esencial al analizar la dinámica cuántica de un conjunto de emisores incrustados dentro de una cavidad. Demostramos que la transferencia eficiente de un estado cuántico de luz en forma de estrella triple al conjunto de emisores solo se puede lograr dentro del límite de un gran número de emisores. Este hallazgo destaca el papel crítico de la escalabilidad en la manipulación exitosa de estados cuánticos y el diseño y optimización de experimentos que involucran dichos sistemas. Además, nuestro estudio reveló que los estados vestidos de fotones y materia se vuelven independientes del número de átomos de dos niveles en el conjunto a medida que aumenta el número de emisores, lo cual se caracteriza por la aparición cíclica de regímenes de antibunching y superbunching. Las ideas obtenidas al explorar la transición de fase de estados coherentes a estados cuántico-correlacionados en las interacciones entre luz y materia nos han permitido comprender mejor la interacción entre cuasipartículas y sus fuerzas de acoplamiento. Identificamos que el conjunto de emisores alcanza la coherencia ligeramente antes que el campo fotónico, destacando la interacción sutil entre los subsistemas de luz y materia. Nuestros hallazgos también han revelado el papel crítico de las correlaciones cuánticas en la determinación del comportamiento general del sistema, enfatizando la importancia de estudiar las propiedades de entrelazamiento en diferentes regímenes. Finalmente, al analizar la dinámica de vórtices polaritónicos utilizando un enfoque completamente cuántico hemos encontrado que la superposición cuántica entre luz y materia conduce a una familia de trayectorias más rica del núcleo del vórtice. El acoplamiento de intercambio cuántico de excitaciones individuales resulta en efectos de interferencia en las trayectorias de los núcleos de vórtices en ambos componentes, con estructuras más complejas que sirven como evidencia sólida del entrelazamiento cuántico entre los componentes polaritónicos.DoctoradoDoctor en Ciencias - FísicaÓptica Cuántica, Materia Condensad