3,566 research outputs found
A scheme for symmetrization verification
We propose a scheme for symmetrization verification in two-particle systems,
based on one-particle detection and state determination. In contrast to
previous proposals, it does not follow a Hong-Ou-Mandel-type approach.
Moreover, the technique can be used to generate superposition states of single
particles
A variant transfer matrix method suitable for transport through multi-probe systems
We have developed a variant transfer matrix method that is suitable for
transport through multi-probe systems. Using this method, we have numerically
studied the quantum spin Hall effect (QSHE) on 2D graphene with both intrinsic
(Vso) and Rashba (Vr) spin-orbit (SO) couplings. The integer QSHE arises in the
presence of intrinsic SO interaction and is gradually destroyed by the Rashba
SO interaction and disorder fluctuation. We have numerically determined the
phase boundaries separating integer QSHE and spin Hall liquid. We have found
that when Vso> 0.2t with t the hopping constant the energy gap needed for the
integer QSHE is the largest satisfying |E|<t. For smaller Vso the energy gap
decreases linearly. In the presence of Rashba SO interaction or disorders, the
energy gap diminishes. With Rashba SO interaction the integer QSHE is robust at
the largest energy within the energy gap while at the smallest energy within
the energy gap the integer QSHE is insensitive to the disorder
Surface Spectral Function of Momentum-dependent Pairing Potentials in a Topological Insulator: Application to CuBiSe
We propose three possible momentum-dependent pairing potentials for candidate
of topological superconductor (for example CuBiSe), and calculate
the surface spectral function and surface density of state with these pairing
potentials. We find that the first two can give the same spectral functions as
the fully-gapped and node-contacted pairing potentials given in [Phys. Rev.
Lett. 105, 097001], and that the third one can obtain topological non-trivial
case which exists flat Andreev bound state and preserves the rotation
symmetry. We hope our proposals and results be judged by future experiment.Comment: 5 pages, 3 figure
Physics for non-physicists - Two bio-degrees reforms in Spanish universities: Health Biology and Biology
We present a review of two different innovative experiences of Physics education for Bio-Sciences in two Spanish Universities - the Health Biology degree of the Universidad de Alcalá de Henares (UAH) and the Biology degree of the Universidad Autónoma de Madrid (UAM). Both experiences took place simultaneously and coincident with the implementation of Bologna Plan. Although they were developed under different contextual constraints, set by the respective Faculties, they share a number of similar pedagogical strategies which are analyzed. In both cases the reforms allowed a substantial improvement in learning results compared to those obtained in the previous Physics courses in the respective degreesLHM participated in the GIREP-MPTL 2018 on behalf of the project IPLS-Spain, promoted and supported by an inter-university group of physics teachers and young biologist
Compositeness effects, Pauli's principle and entanglement
We analyse some compositeness effects and their relation with entanglement.
We show that the purity of a composite system increases, in the sense of the
expectation values of the deviation operators, with large values of the
entanglement between the components of the system. We also study the validity
of Pauli's principle in composite systems. It is valid within the limits of
application of the approach presented here. We also present an example of two
identical fermions, one of them entangled with a distinguishable particle,
where the exclusion principle cannot be applied. This result can be important
in the description of open systems
Stream Learning in Energy IoT Systems: A Case Study in Combined Cycle Power Plants
The prediction of electrical power produced in combined cycle power plants is a key challenge in the electrical power and energy systems field. This power production can vary depending on environmental variables, such as temperature, pressure, and humidity. Thus, the business problem is how to predict the power production as a function of these environmental conditions, in order to maximize the profit. The research community has solved this problem by applying Machine Learning techniques, and has managed to reduce the computational and time costs in comparison with the traditional thermodynamical analysis. Until now, this challenge has been tackled from a batch learning perspective, in which data is assumed to be at rest, and where models do not continuously integrate new information into already constructed models. We present an approach closer to the Big Data and Internet of Things paradigms, in which data are continuously arriving and where models learn incrementally, achieving significant enhancements in terms of data processing (time, memory and computational costs), and obtaining competitive performances. This work compares and examines the hourly electrical power prediction of several streaming regressors, and discusses about the best technique in terms of time processing and predictive performance to be applied on this streaming scenario.This work has been partially supported by the EU project iDev40. This project has received funding
from the ECSEL Joint Undertaking (JU) under grant agreement No 783163. The JU receives support from the
European Union’s Horizon 2020 research and innovation programme and Austria, Germany, Belgium, Italy,
Spain, Romania. It has also been supported by the Basque Government (Spain) through the project VIRTUAL
(KK-2018/00096), and by Ministerio de Economía y Competitividad of Spain (Grant Ref. TIN2017-85887-C2-2-P)
Dielectric Function of Diluted Magnetic Semiconductors in the Infrared Regime
We present a study of the dielectric function of metallic (III,Mn)V diluted
magnetic semiconductors in the infrared regime. Our theoretical approach is
based on the kinetic exchange model for carrier induced (III,Mn)V
ferromagnetism. The dielectric function is calculated within the random phase
approximation and, within this metallic regime, we treat disorder effects
perturbatively and thermal effects within the mean field approximation. We also
discuss the implications of this calculations on carrier concentration
measurements from the optical f-sum rule and the analysis of plasmon-phonon
coupled modes in Raman spectra.Comment: 6 pages, 6 figures include
- …