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

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

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

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

Faraday rotation and transmittance as markers of topological phase transitions in 2D materials

We analyze the magneto-optical conductivity (and related magnitudes like transmittance and Faraday rotation of the irradiated polarized light) of some elemental twodimensional Dirac materials of group IV (graphene analogues, buckled honeycomb lattices, like silicene, germanene, stannane, etc.), group V (phosphorene), and zincblende heterostructures (like HgTe/CdTe quantum wells) near the Dirac and gamma points, under out-of-plane magnetic and electric fields, to characterize topological-band insulator phase transitions and their critical points. We provide plots of the Faraday angle and transmittance as a function of the polarized light frequency, for different external electric and magnetic fields, chemical potential, HgTe layer thickness and temperature, to tune the material magneto-optical properties. We have shown that absortance/transmittance acquires extremal values at the critical point, where the Faraday angle changes sign, thus providing fine markers of the topological phase transition. In the case of non-topological materials as phosphorene, a minimum of the transmittance is also observed due to the energy gap closing by an external electric field.Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (through Organization: Consejería de Economía Innovación Ciencia y Empleo)Ministerio de Ciencia e InnovaciónUniversidad Nacional Autónoma de México / National Autonomous University of Mexico [UNAM

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

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

Analogies between the topologial insulator phase of 2D Dirac materials and the superradiant phase of atom-field systems

A semiclassical phase-space perspective of band- and topological-insulator regimes of 2D Dirac materials and normal- and superradiant phases of atom-field interacting models is given in terms of delocalization, entropies, and quantum correlation measures. From this point of view, the low-energy limit of tight-binding models describing the electronic band structure of topological 2D Dirac materials such as phosphorene and silicene with tunable band gaps share similarities with Rabi-Dicke and Jaynes-Cummings atom-field interaction models, respectively. In particular, the edge state of the 2D Dirac materials in the topological insulator phase exhibits a Schrödinger's cat structure similar to the ground state of two-level atoms in a cavity interacting with a one-mode radiation field in the superradiant phase. Delocalization seems to be a common feature of topological insulator and superradiant phases.Spanish MICIU and Junta de Andalucía through the projects PGC2018-097831-B-I00, SOMM17/6105/UGR, UHU-1262561 and FQM-381Project DGAPA:IN10161

Phase-space Fisher information of 2D gapped Dirac materials

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

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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