Hot-filament metal oxide deposition (HFMOD): a novel method for depositing thin films of metallic oxides

This short report describes a novel method for the synthesis of metal oxide thin films. The experimental setup consists of a metal filament installed inside a vacuum chamber. The filament can be heated by an ac power supply while oxygen is admitted into the chamber using a mass flowmeter. From reactions between oxygen and the heated metal filament, volatile oxide species, Me xOy, where Me is the metal, can be formed, condensing on a nearby substrate. We have observed that thin films of WxOy and Mo xOy can be satisfactorily deposited by this novel method. Although several techniques were used to characterize the oxides, this note emphasizes the results obtained by X-ray Photoelectron Spectroscopy (XPS).O presente artigo descreve um novo método para a síntese de filmes finos de óxidos metálicos. Um filamento de metal, que pode ser aquecido por uma fonte de corrente alternada é instalado numa câmara de vácuo. Por meio de um fluxômetro de massa, oxigênio pode ser admitido no interior da câmara. Da reação entre o oxigênio e o metal do filamento aquecido, espécies de óxidos voláteis Me xOy, onde Me é o metal, são formadas, se condensando num substrato colocado próximo ao filamento, formando o filme. Foi observado que os filmes finos de WxOy e Mo xOy podem ser depositados de forma satisfatória por este novo método. Embora várias outras técnicas de análise tenham sido usadas para caracterizar os óxidos, esta nota enfatiza os resultados obtidos por espectroscopia de fotoelétrons de raio-X (XPS).324326Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Mode structure in superconducting metamaterial transmission-line resonators

FUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSuperconducting metamaterials are a promising resource for quantum-information science. In the context of circuit QED, they provide a means to engineer on-chip dispersion relations and a band structure that could ultimately be utilized for generating complex entangled states of quantum circuitry, for quantum-reservoir engineering, and as an element for quantum-simulation architectures. Here we report on the development and measurement at millikelvin temperatures of a particular type of circuit metamaterial resonator composed of planar superconducting lumped-element reactances in the form of a discrete left-handed transmission line that is compatible with circuit QED architectures. We discuss the details of the design, fabrication, and circuit properties of this system. As well, we provide an extensive characterization of the dense mode spectrum in these metamaterial resonators, which we conduct using both microwave-transmission measurements and laser-scanning microscopy. Results are observed to be in good quantitative agreement with numerical simulations and also an analytical model based upon current-voltage relationships for a discrete transmission line. In particular, we demonstrate that the metamaterial mode frequencies, spatial profiles of current and charge densities, and damping due to external loading can be readily modeled and understood, making this system a promising tool for future use in quantum-circuit applications and for studies of complex quantum systems.115120FUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESTADO DE SANTA CATARINACNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSem informaçãoSem informaçãoAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

Qubit-flip-induced cavity mode squeezing in the strong dispersive regime of the quantum Rabi model

Squeezed states of light are a set of nonclassical states in which the quantum fluctuations of one quadrature component are reduced below the standard quantum limit. With less noise than the best stabilised laser sources, squeezed light is a key resource in the field of quantum technologies and has already improved sensing capabilities in areas ranging from gravitational wave detection to biomedical applications. In this work we propose a novel technique for generating squeezed states of a confined light field strongly coupled to a two-level system, or qubit, in the dispersive regime. Utilising the dispersive energy shift caused by the interaction, control of the qubit state produces a time-dependent change in the frequency of the light field. An appropriately timed sequence of sudden frequency changes reduces the quantum noise fluctuations in one quadrature of the field well below the standard quantum limit. The degree of squeezing and the time of generation are directly controlled by the number of frequency shifts applied. Even in the presence of realistic noise and imperfections, our protocol promises to be capable of generating a useful degree of squeezing with present experimental capabilities

Measurements Of Nanoresonator-qubit Interactions In A Hybrid Quantum Electromechanical System

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Experiments to probe the basic quantum properties of motional degrees of freedom of mechanical systems have developed rapidly over the last decade. One promising approach is to use hybrid electromechanical systems incorporating superconducting qubits and microwave circuitry. However, a critical challenge facing the development of these systems is to achieve strong coupling between mechanics and qubits while simultaneously reducing coupling of both the qubit and mechanical mode to the environment. Here we report measurements of a qubit-coupled mechanical resonator system consisting of an ultra-high-frequency nanoresonator and a long coherence-time superconducting transmon qubit, embedded in a superconducting coplanar waveguide cavity. It is demonstrated that the nanoresonator and transmon have commensurate energies and transmon coherence times are one order of magnitude larger than for all previously reported qubit-coupled nanoresonators. Moreover, we show that numerical simulations of this new hybrid quantum system are in good agreement with spectroscopic measurements and suggest that the nanoresonator in our device resides at low thermal occupation number, near its ground state, acting as a dissipative bath seen by the qubit. We also outline how this system could soon be developed as a platform for implementing more advanced experiments with direct relevance to quantum information processing and quantum thermodynamics, including the study of nanoresonator quantum noise properties, reservoir engineering, and nanomechanical quantum state generation and detection.2736National Science Foundation [ECCS-1542081, DMR-1056423, DMR-1312421]Instituto Nacional de Ciencia e Tecnologia-Informacao Quantica (INCT-IQ)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2012/51589-1]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Internationale Zusammenarbeit in Schluesselindustrien

Includes 6 articlesAvailable from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel A 160820 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Pork Liver Freshness Evaluated through Spoilage Microbiota and a Consumer Test in Shelf Life Extension Experiment

Pork liver is an affordable product, very much appreciated by some consumers. Packaged pork liver has a short shelf life that can represent an additional cost to the producers. This work aimed to assess the relationship between consumer acceptability, evaluated through both a test made live with photography and samples to be smelled and an internet survey platform based only on photography, and the counts of the main spoilage microorganisms, on pork liver samples stored from the actual end of shelf life (ESL) and two extra days of storage times, ESL + 2 and ESL + 4. The results indicate limited usefulness of microbial counts, once they were generally very similar between accepted and nonaccepted samples, with total viable count below 7 Log CFU/g. Both methodological approaches revealed that there is no margin to extend the shelf life from the three days previously established by the manufacturer. It was observed that pork liver packaged with modified atmosphere had similar evaluations of freshness using internet-based or live test with consumers, with a drop in purchase intention from 87.5% at ESL to 13.2% at ESL + 2, when the assessment was made through the internet-based test. When the test was made live, the purchase intention had the same trend, but the drop was smaller, from 61.5 at ESL to 21.2% at ESL + 2. The purchasing intention was lower when the consumers had the opportunity to smell the samples but considering the decision of defining the end of shelf life based on 50% of consumers accepting, it was similar in almost all the cases