Generation of Superposition States and Charge-Qubit Relaxation Probing in a Circuit

We demonstrate how a superposition of coherent states can be generated for a microwave field inside a coplanar transmission line coupled to a single superconducting charge qubit, with the addition of a single classical magnetic pulse for chirping of the qubit transition frequency. We show how the qubit dephasing induces decoherence on the field superposition state, and how it can be probed by the qubit charge detection. The character of the charge qubit relaxation process itself is imprinted in the field state decoherence profile.Comment: 6 pages, 4 figure

Temperature Measurement and Phonon Number Statistics of a Nanoelectromechanical Resonator

Measuring thermodynamic quantities can be easy or not, depending on the system that is being studied. For a macroscopic object, measuring temperatures can be as simple as measuring how much a column of mercury rises when in contact with the object. At the small scale of quantum electromechanical systems, such simple methods are not available and invariably detection processes disturb the system state. Here we propose a method for measuring the temperature on a suspended semiconductor membrane clamped at both ends. In this method, the membrane is mediating a capacitive coupling between two transmission line resonators (TLR). The first TLR has a strong dispersion, that is, its decaying rate is larger than its drive, and its role is to pump in a pulsed way the interaction between the membrane and the second TLR. By averaging the pulsed measurements of the quadrature of the second TLR we show how the temperature of the membrane can be determined. Moreover the statistical description of the state of the membrane, which is directly accessed in this approach is significantly improved by the addition of a Josephson Junction coupled to the second TLR.Comment: 9 pages, 5 figures. To appear in New Journal of Physic

Capacitive Coupling of Two Transmission Line Resonators Mediated by the Phonon Number of a Nanoelectromechanical Oscillator

Detection of quantum features in mechanical systems at the nanoscale constitutes a challenging task, given the weak interaction with other elements and the available technics. Here we describe how the interaction between two monomodal transmission-line resonators (TLRs) mediated by vibrations of a nano-electromechanical oscillator can be described. This scheme is then employed for quantum non-demolition detection of the number of phonons in the nano-electromechanical oscillator through a direct current measurement in the output of one of the TLRs. For that to be possible an undepleted field inside one of the TLR works as a amplifier for the interaction between the mechanical resonator and the remaining TLR. We also show how how the non-classical nature of this system can be used for generation of tripartite entanglement and conditioned mechanical coherent superposition states, which may be further explored for detection processes.Comment: 6 pages, 5 figure

Quantum simulation of the Anderson Hamiltonian with an array of coupled nanoresonators: delocalization and thermalization effects

The possibility of using nanoelectromechanical systems as a simulation tool for quantum many-body effects is explored. It is demonstrated that an array of electrostatically coupled nanoresonators can effectively simulate the Bose-Hubbard model without interactions, corresponding in the single-phonon regime to the Anderson tight-binding model. Employing a density matrix formalism for the system coupled to a bosonic thermal bath, we study the interplay between disorder and thermalization, focusing on the delocalization process. It is found that the phonon population remains localized for a long time at low enough temperatures; with increasing temperatures the localization is rapidly lost due to thermal pumping of excitations into the array, producing in the equilibrium a fully thermalized system. Finally, we consider a possible experimental design to measure the phonon population in the array by means of a superconducting transmon qubit coupled to individual nanoresonators. We also consider the possibility of using the proposed quantum simulator for realizing continuous-time quantum walks.Comment: Replaced with new improved version. To appear in EPJ Q

Desempenhos produtivos de cruzamentos de ovinos das raças Santa Inês, Somalis Brasileira, Dorper e Poll Dorset no Brasil.

Resumo: A partir de registros de peso ao nascer (PN), peso ao desmame (PD) e ganho de peso entre nascimento e desmame (GP), foram estimados os efeitos de diferença genética aditiva entre as raças Santa Inês (SI), Somalis Brasileira (So), Dorper (Do) e Poll Dorset (Po), de dominância e de recombinação. Foram utilizados 3.573 registros de PN e 2.797 registros de PD e GP. Análises com modelo animal foram realizadas considerando os efeitos de diferença genética aditiva entre as raças, de dominância e de recombinação como covariáveis. Observou-se diferença significativa para a genética individual das raças Poll Dorset e Somalis Brasileira para PN, PD e GP. Para PD, também foi encontrada significância para a heterose direta Do x So e SI x So e para a heterose materna Do x SI, Do x So, Po x SI, Po x So e SI x So. Para GP, também foi encontrada significância para a recombinação e para as heteroses maternas Do x Po, Do x SI, Do x So, Po x SI, Po x So e SI x So. A manutenção de elevados níveis de heterozigose individual e materna tem grande importância, proporcionando animais com melhores desempenhos. [Productive Performance of Crossbreeding of Santa Inês, Somalis Brasileira, Dorper and Poll Dorset breeds sheep in Brazil]. Abstract: From records of birth weight (PN), weaning weight (PD) and pre-weaning weight gain (GP), effects of additive genetic difference among Santa Ines (SI), Somalis Brasileira (So), Dorper (Do) and Poll Dorset (Po) breeds, effects of dominance and recombination were estimated. 3,573 records of PN and 2,797 records of PD and GP were utilized. Animal models analyses were performed considering the effects of additive genetic difference between the breeds and the effects of dominance and of recombination as covariates. There was a significant individual genetic difference for Poll Dorset and Somalis Brasileira breeds for PN, PD and GP. For PD, the direct heterosis of Do x So and SI x So and the maternal heterosis for Do x SI, Do x So, Po x SI, Po x So and SI x So were significant. For GP, the recombination and the maternal heterosis for Do x Po, Do x SI, Do x So, Po x SI, Po x So and SI x So were significant. The maintenance of high levels of individual and maternal heterozygosis has great importance, providing animals with better performance

Estimation of kinetic parameters in a chromatographic separation model via Bayesian inference

A modelagem de processos de adsorção tem sido empregada com frequência nas indústrias químicas, petroquímicas e refinarias, por exemplo para separação e purificação de misturas em unidade de Leito Móvel Simulado (LMS). Na representação matemática do modelo, a determinação de parâmetros é um passo importante para o projeto de condições cromatográficas para a separação contínua, em processos do tipo LMS. Este trabalho tem por objetivo a análise de estimativa de parâmetros em processos de adsorção, usando um sistema cromatográfico com uma coluna, para a separação das substâncias Glicose e Frutose. Investiga-se o uso da abordagem Bayesiana, através de métodos de Monte Carlo via Cadeias de Markov (MCMC), assim como o uso da abordagem da máxima verossimilhança, utilizando duas técnicas estocásticas diferentes, o Algoritmo de Colisão de Partículas (PCA - Particle Collision Algorithm), e o Algoritmo de Otimização por Enxame de Partículas (PSO - Particle Swarm Optimization) para executar a tarefa de minimização da função objetivo. Diferentes casos são apresentados com o objetivo de analisar a significância estatística das estimativas obtidas para os parâmetros, fazendo-se uma comparação crítica entre a solução via inferência Bayesiana e via minimização da função objetivo com métodos estocásticos. Os resultados obtidos demonstram que o uso da abordagem Bayesiana fornece uma proposta vantajosa para a estimativa de parâmetros em transferência de massa, oferecendo resultados com maior riqueza de informação estatística.The modeling of adsorption processes appears quite frequently in the chemical industry, petrochemical plants and refineries, for example for separation and purification of mixtures in Simulated Moving Bed (SMB) units. In the mathematical formulation, the accurate determination of the model parameters is an important step for the design of chromatographic conditions for continuous separation in SMB processes. This work is aimed at the estimation of the model parameters in adsorption processes, using a chromatographic column for the separation of glucose and fructose. The Bayesian framework for inverse problems is investigated through the implementation of Markov Chain Monte Carlo methods (MCMC) and a critical comparison against the classical Maximum Likelihood approach, with the minimization of the objective function via two different stochastic techniques, namely the Particle Collision Algorithm (PCA), and the Particle Swarm Optimization (PSO) is performed. Different cases are presented in order to investigate the statistical significance of the estimates obtained, and perform comparisons between the solution via Bayesian inference and via the minimization of the objective function with the stochastic methods. The results demonstrate that the Bayesian approach employs less computational effort to achieve estimates with comparable statistical information.Peer Reviewe

Produção de feno no Semi-Árido.

Producão de feno a partir de grarníneas e legurninosas; Algumas árvores e arbustos nativos e exóticos adaptados ao Semi-Árido com potencial forrageiro; Faveira-de-bolota (Parkia platycephala); Leucena(Leucaena leucocephala); Feijão-guandu(Cajanus cajan); Sabiá(Mimosa caesalpiniaefolia); Pau-ferro(Caesalpinia ferrea); Jurerninha(Desmanthus virgatus); Mororó (Bauhinia cheilantha); Camaratuba(Cratylia argentea); Algaroba(Prosopis juliflora); Gliricídia(Gliricidia sepium); Juazeiro(Ziziphus spp.); Maniçoba(Mnihot pseudo glaziovii); Algodão-de-seda(Calotropis procera); Mandioca, macaxeira(Manihot esculenta); Mata-pasto(Senna obtusifolia); Bordão-de-velho(Samanea saman); Jurema-preta(Mimosa tenuiflora).bitstream/item/35908/1/Doc149.pd

Desempenho produtivo de cultivares de amendoim para a região Meio-Norte do Brasil.

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