8 research outputs found

    Characterization of a quantum phase transition in Dirac systems by means of the wavepacket dynamics

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    We study the signatures of phase transitions in the time evolution of wave-packets by analyzing two simple model systems: a graphenequantum dot model in a magnetic field and a Diracoscillator in a magnetic field. We have characterized the phase transitions using the autocorrelation function. Our work also reveals that the description in terms of Shannon entropy of the autocorrelation function is a clear phase transition indicator.This work was supported by Spanish MICINN projects FIS2011-24149 and FIS2009-08451, CEI BioTic UGR project 20F12.41 and Junta de Andalucia projects FQM-165/0207 and FQM219

    Quantum recurrence times in nanostructures

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    We compute the classical and revival times of electron currents in several bulk nanostructured, semiconductor materials. We have used a nonparabolic Schrödinger equation to model the conduction band of semiconductors. We have calculated the classical and revival periods for quantum dots of Si, Ge and InAs quantum dots. The obtained results are of the order of tenths of nanoseconds to picoseconds, which are within reach of current technologies.This work is part of the Project of I+D+i Ref. PID2020-113681GB-I00, financed by MICIN/AEI/10.13039/501100011033 and FEDER “A way to make Europe”

    Signatures of topological phase transitions in higher Landau levels of HgTe/CdTe quantum wells from an information theory perspective

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    We analyze the structure of low energy Hamiltonian eigenstates in zincblende heterostructures (like HgTe/CdTe quantum wells) near the gamma point, under magnetic fields, to characterize topological phase transitions (TPT) under an information-theoretic perspective. Using information markers like entanglement, quantum fluctuations, fidelity susceptibility, participation ration, area in phase space, etc., we realize that higher Landau levels (LL) feel the topological phase transition slightly displaced with regard to the edge state, thus leading to the concept of ‘‘higher Landau level |n| > 0 TPT’’, as ‘‘echoes’’ of the standard edge state n = 0 TPT. We compute the critical magnetic field and the critical HgTe layer thickness at which these information measures of higher Landau levels undergo a structural change.PGC2018-097831-B-I00UHU-1262561 and FQM-381Universidad de Granada / CBU

    Estudio de las densidades electrónicas de carga, de momento y de pares en sistemas atómicos

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    El conocimiento riguroso que se tiene actualmente sobre las densidades a uno y dos cuerpos de los sistemas atómicos en su estado fundamental es muy escaso. El primer objetivo de este trabajo ha sido la exploración de la existencia de propiedades de monotonía y, en su caso, de modalidad de validez general, en las densidades mono-electrónicas de carga y de momento y de pares en la aproximación Hartree-Fock para un conjunto de átomos del sistema periódico (específicamente, del hidrógeno al uranio) y sus consecuencias en el conocimiento de las magnitudes fundamentales y/o experimentalmente medibles del sistema atómico considerado. Asimismo se analiza el concepto de entropía de Fisher y se muestra su conexión con magnitudes fundamentales del sistema.Universidad de Granada, Departamento de Física Moderna. Leída 16-12-9

    Phase-space Fisher information of 2D gapped Dirac materials

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    It is shown that phase-space Fisher information marks topological phase transitions in 2D Dirac gapped materials. The phase-space Fisher information determined for electrons and holes exhibit minimum at the charge neutrality points. Topological quantum numbers are defined to identify different phases utilizing combined information measures. Upper and lower bounds are derived for the phase-space Fisher information.The work was supported by the Junta de Andalucía Project FQM-381 and the National Research,Development and Innovation Fund of Hungary, financed under the 123988 funding scheme and the EU-funded Hungarian Grant EFOP- 3.6.2-16-2017-00005

    Expansion and application of the PREDA material and its effects on Academic Dishonesty and its attitudes

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    La Deshonestidad Académica (DA) es una de las grandes dificultades que está teniendo la universidad en la formación de futuros profesionales. El objetivo del trabajo fue ampliar el material PREDA con una nueva unidad sobre el software empleado para la detección del plagio y analizar analizar el efecto de todo el PREDA en la percepción de la DA en estudiantes universitarios. La muestra total es de 472 estudiantes universitarios de la UCM y la UDIMA de 15 asignaturas diferente, tanto de grado como de máster. Los resultados indican que no existe un efecto significativo de las estrategías en la percepción de la DA. Sin embargo, el grupo de estudiantes que se expuso al material diseñado y que fue trabajado en el aula presenta una mejora en la percepción de la DA. El material diseñado puede ser empleado para tratar el tema de la DA al interior del aula.Academic Dishonesty (AD) is one of the great difficulties that the university is having in the training of future professionals. The objective of the work was to expand the PREDA material with a new unit on the software used to detect plagiarism and to analyze the effect of all the PREDA on the perception of AD in university students. The total sample is 472 university students from the UCM and the UDIMA of 15 different subjects, both undergraduate and master's degrees. The results indicate that there is no significant effect of the strategies on the perception of AD. However, the group of students who were exposed to the material designed and worked on in the classroom presented an improvement in the perception of AD. The material designed can be used to deal with the subject of AD in the classroom.Depto. de Investigación y Psicología en EducaciónFac. de EducaciónFALSEVicerrectorado de Calidad - UCMunpu

    ESICM LIVES 2016: part two : Milan, Italy. 1-5 October 2016.

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