633 research outputs found
Shortcuts to adiabaticity in superconducting circuits for fast multi-partite state generation
Shortcuts to adiabaticity provides a flexible method to accelerate and
improve a quantum control task beyond adiabatic criteria. Here we propose the
reverse-engineering approach to design the longitudinal coupling between a set
of qubits coupled to several field modes, for achieving a fast generation of
multi-partite quantum gates in photonic or qubit-based architecture. We show
that the enhancing generation time is at the nanosecond scale that does not
scale with the number of system components. In addition, our protocol does not
suffer noticeable detrimental effects due to the dissipative dynamics. Finally,
the possible implementation is discussed with the state-of-the-art circuit
quantum electrodynamics architecture.Comment: 11 pages, 8 figure
Embedded Quantum Correlations in thermalized quantum Rabi systems
We study the quantum correlations embedded in open quantum Rabi systems.
Specifically, we study how the quantum correlation depends on the coupling
strength, number of qubits, and reservoir temperatures. We numerically
calculate the quantum correlations of up to three qubits interacting with a
single field mode. We find that the embedded quantum correlations exhibit a
maximum for a given coupling strength, which depends inversely on the number of
subsystems and the reservoir temperature. We explore how this feature affects
the performance of a many-qubit Otto heat engine, finding numerical evidence of
a direct correspondence between the minimum of the extractable work and the
maximum of the embedded quantum correlations in the qubit-cavity bi-partition.
Furthermore, as we increase the number of qubits, the maximum extractable work
is reached at smaller values of the coupling strength. This work could help
design more sophisticated quantum heat engines that rely on many-body systems
with embedded correlations as working substances.Comment: 12 pages and 12 figure
Multiqubit and multilevel quantum reinforcement learning with quantum technologies
We propose a protocol to perform quantum reinforcement learning with quantum technologies. At variance with recent results on quantum reinforcement learning with superconducting circuits, in our current protocol coherent feedback during the learning process is not required, enabling its implementation in a wide variety of quantum systems. We consider diverse possible scenarios for an agent, an environment, and a register that connects them, involving multiqubit and multilevel systems, as well as open-system dynamics. We finally propose possible implementations of this protocol in trapped ions and superconducting circuits. The field of quantum reinforcement learning with quantum technologies will enable enhanced quantum control, as well as more efficient machine learning calculations.We acknowledge support from CEDENNA basal grant No. FB0807 and Direccion de Postgrado USACH (FAC-L), FONDECYT under grant No. 1140194 (JCR), Spanish MINECO/FEDER FIS2015-69983-P and Basque Government IT986-16 (LL and ES), and Ramon y Cajal Grant RYC-2012-11391 (LL)
Tripartite entanglement in quantum memristors
We study the entanglement and memristive properties of three coupled quantum
memristors. We consider quantum memristors based on superconducting asymmetric
SQUID architectures which are coupled via inductors. The three quantum
memristors are arranged in two different geometries: linear and triangular
coupling configurations. We obtain a variety of correlation measures, including
bipartite entanglement and tripartite negativity. We find that, for identical
quantum memristors, entanglement and memristivity follow the same behavior for
the triangular case and the opposite one in the linear case. Finally, we study
the multipartite correlations with the tripartite negativity and entanglement
monogamy relations, showing that our system has genuine tripartite
entanglement. Our results show that quantum correlations in multipartite
memristive systems have a non-trivial role and can be used to design quantum
memristor arrays for quantum neural networks and neuromorphic quantum computing
architectures.Comment: 9 pages, 6 figure
Microwave Quantum Memristors
We propose a design of a superconducting quantum memristive device in the
microwave regime, that is, a microwave quantum memristor. It comprises two
linked resonators, where the primary one is coupled to a superconducting
quantum interference device (SQUID), allowing the adjustment of the resonator
properties with an external magnetic flux. The auxiliary resonator is operated
through weak measurements, providing feedback to the primary resonator via the
SQUID and establishing stable memristive behavior via the external magnetic
flux. The device operates with a classical input signal in one cavity while
reading the response in the other, serving as a fundamental building block for
arrays of microwave quantum memristors. In this sense, we observe that a
bipartite setup can retain its memristive behavior while gaining entanglement
and quantum correlations. Our findings open the door to the experimental
implementation of memristive superconducting quantum devices and arrays of
microwave quantum memristors on the path to neuromorphic quantum computing.Comment: 9+6 pages, 10 figure
Diet of Engystomops pustulosus (Anura: Leptodactylidae) from Colombia and current knowledge of its dietary
Investigamos la dieta de Engystomops pustulosus de una población del valle medio del río Magdalena, incluyendo una evaluación del efecto del tamaño del cuerpo y de la cabeza sobre el número y volumen de presas. Presentamos el estado actual de conocimiento sobre la dieta de E. pustulosus a partir de información publicada más nuestros datos. Encontramos un total de 400 presas representando dos phyla, Arthropoda y Mollusca; siete órdenes y nueve familias de invertebrados. Los artrópodos, principalmente insectos, fueron las presas más frecuentes en la dieta. Entre los artrópodos, Acari e Isoptera fueron numéricamente dominantes. No se observaron efectos del tamaño del cuerpo y la cabeza sobre el número y volumen de presas. La literatura publicada sobre la dieta de E. pustulosus incluyó 66 taxones presas, entre los que Isoptera, Acari y Formicidae fueron los grupos más comunes, lo que sugiere una especialización en la dieta. Las presas consumidas por E. pustulosus varían entre localidades; Blattodea, Orthoptera y Thysanoptera, son únicos en algunas localidades. Estudios más detallados de la disponibilidad de presas y dietas asociadas a los cambios en el uso del suelo en mas localidades geográficas contribuirá a una mejor comprensión de las interacciones depredador-presa en estos entornos antropogénicos.Investigamos a dieta de Engystomops pustulosus de uma população do vale médio do rio Magdalena, incluindo uma avaliação do efeito do tamanho do corpo e da cabeça sobre o número e o volume das presas. Apresentamos o estado atual do conhecimento sobre a dieta de E. pustulosus com base em informações publicadas e em nossos próprios dados. Encontramos um total de 400 itens alimentares representando os filos Arthropoda e Mollusca; sete ordens e nove famílias de invertebrados. Artrópodes, principalmente insetos, foram os itens mais frequentes na dieta. Entre os artrópodes, Acari e Isoptera foram numericamente dominantes. Não foram observados efeitos do tamanho do corpo e da cabeça sobre o número e o volume de presas. A literatura publicada sobre a dieta de E. pustulosus incluiu 66 táxons, entre os quais Isoptera, Acari e Formicidae foram os grupos mais comuns, sugerindo especialização na dieta. Os itens consumidos variaram entre as localidades; Blattodea, Orthoptera e Thysanoptera foram exclusivos de algumas localidades. Estudos mais detalhados da disponibilidade de presas e dietas associadas a mudanças no uso do solo em mais localidades geográficas contribuirão para uma melhor compreensão das interações predador-presanesses ambientes antropogênicos.We investigated the diet of Engystomops pustulosus from a population in the Middle Magdalena River valley, including an evaluation of theeffect of body and head size on prey number and volume. We present the current state of knowledge of the diet of E. pustulosus from published information in addition to our data. We found a total of 400 prey items representing two phyla, Arthropoda and Mollusca; seven orders and nine families were detected. Arthropods, mainly insects, were the most frequent prey in the diet. Among arthropods, Acari and Isoptera were numerically dominant. We did not observe effects of body and head size on prey number and volume. The published literature of the diet of E. pustulosus included 66 prey items, among which Isoptera (termites), Acari, and Formicidae were the most common groups, suggesting dietary specialization. Prey items consumed by E. pustulosus varied among different localities; Blattodea, Orthoptera, and Thysanoptera were unique at certain localities. Further study of prey availability and diets associated with land-use changes across majorgeographic localities will contribute to a better understanding of the predator-prey interactions in these anthropogenic environments
Efecto del ejercicio y la actividad física sobre las funciones ejecutivas en niños y en jóvenes. Una revisión sistemática
This qualitative systematic review tries to advance knowledge about the effect of physical activity on executive functions, paying special attention to healthy children, teenagers and youngsters. Several articles have been identified, categorized and analyzed in electronic databases such as ISI Web of Knowledge, SCOPUS, PubMed, SPORTDiscus, PsyINFO, ERIC, Google Scholar and Dialnet. According to the inclusion/exclusion criteria, following the PRISMA statement to record and categorize the results and throughout the quality assessment tool "The Effective Public Health Practice Project”, 44 pieces of research, structured in acute and chronic episodes of physical activity under two approaches: qualitative and quantitative, were chosen. The results show a higher number of experiments with quantitative acute episodes (45,45%) against qualitative ones (18,18%), chronic quantitative (20,45%) and chronic qualitative episodes (15,92%). The analysis of these investigations has allowed identifying the benefits of different types of physical activity studied on executive components.En la presente revisión sistemática cualitativa se intenta avanzar en el conocimiento sobre la incidencia de la actividad física sobre las funciones ejecutivas, focalizada en poblaciones sanas infantiles, adolescentes y jóvenes. Se identificaron, categorizaron y analizaron artículos de bases de datos electrónicas como ISI Web of Knowledge, SCOPUS, PubMed, SPORTDiscus, PsyINFO, ERIC, Google Scholar y Dialnet. Atendiendo a los criterios de inclusión/exclusión, siguiendo la declaración PRISMA para registrar y categorizar los resultados, y mediante la herramienta de evaluación de calidad “The Effective Public Health Practice Project”, se seleccionaron finalmente 44 investigaciones experimentales, estructuradas en episodios agudos y crónicos de actividad física bajo dos enfoques: cuantitativos y cualitativos. Los resultados muestran una superior cantidad de experimentos con episodios agudos cuantitativos (45,45%), frente a los agudos cualitativos (18,18%), crónicos cuantitativos (20,45%) y crónicos cualitativos (15,92%). Los análisis de estas investigaciones han permitido identificar los beneficios de los diferentes tipos de actividad física estudiados sobre los componentes ejecutivos
Creatividad táctica y funciones ejecutivas en los deportes de interacción
Tactical creativity is one of the characteristics of the players with greater expertise in interactive (or contact) sports. The term is defined as the ability to generate original and surprising answers to the problems that arise during the game. Recent research has shown that these athletes have certain cognitive capacities, known as executive functions, which could explain this superiority. Experimental studies conducted with children conclude that the repeated practice of physical activity in environments with high levels of entropy could improve these executive functions. On the other hand, it has been seen that the use of intentional strategies by the coach, meant to address the behavior of athletes, can be detrimental to the development of tactical creativity. This review describes the evidence and offers a practical proposal on the design of learning environments promoting this capacity through the control of the task complexity and the feedback of the coach.La creatividad táctica es una de las características de los jugadores con mayor pericia en deportes de interacción. Ésta se define como la capacidad para generar respuestas sorpresivas y originales ante los problemas que surgen durante el juego. Recientes investigaciones han comprobado que estos deportistas poseen ciertas capacidades cognitivas, conocidas como funciones ejecutivas, que podrían explicar esta superioridad. Estudios experimentales llevados a cabo con niños concluyen que la práctica repetida de actividad física en entornos con elevados niveles de entropía podría mejorar estas funciones ejecutivas. Por otro lado, se ha visto que el uso de estrategias intencionales por parte del entrenador para dirigir la conducta de los deportistas puede ser perjudicial para el desarrollo de la creatividad táctica. En esta revisión se describe esta evidencia y se realiza una propuesta práctica sobre cómo diseñar entornos de aprendizaje para promover esta capacidad a través del control de la complejidad de la tarea y del feedback del entrenador
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