Correlated few-electron states in vertical double-quantum-dot systems

The electronic properties of semiconductor, vertical, double quantum dot systems with few electrons are investigated by means of analytic, configuration-interaction, and mean-field methods. The combined effect of a high magnetic field, electrostatic confinement, and inter-dot coupling, induces a new class of few-electron ground states absent in single quantum dots. In particular, the role played by the isospin (or quantum dot index) in determining the appearance of new ground states is analyzed and compared with the role played by the standard spin.Comment: 20 pages, Latex, figures upon request. To appear in Phys. Rev. B (January 1995

Physical Layer Security: Detection of Active Eavesdropping Attacks by Support Vector Machines

This paper presents a framework for converting wireless signals into structured datasets, which can be fed into machine learning algorithms for the detection of active eavesdropping attacks at the physical layer. More specifically, a wireless communication system, which consists of K legal users, one access point (AP) and one active eavesdropper, is considered. To cope with the eavesdropper who breaks into the system during the uplink phase, we first build structured datasets based on several different features. We then apply support vector machine (SVM) classifiers and one-class SVM classifiers to those structured datasets for detecting the presence of eavesdropper. Regarding the data, we first process received signals at the AP and then define three different features (i.e., MEAN, RATIO and SUM) based on the post-processing signals. Noticeably, our three defined features are formulated such that they have relevant statistical properties. Enabling the AP to simulate the entire process of transmission, we form the so-called artificial training data (ATD) that is used for training SVM (or one-class SVM) models. While SVM is preferred in the case of having perfect channel state information (CSI) of all channels, one-class SVM is preferred in the case of having only the CSI of legal users. We also evaluate the accuracy of the trained models in relation to the choice of kernel functions, the choice of features, and the change of eavesdropper's power. Numerical results show that the accuracy is relatively sensitive to adjusting parameters. Under some settings, SVM classifiers (or even one-class SVM) can bring about the accuracy of over 90%.Comment: All versions on this site are withdrawn because of their serious mistakes. Moreover, the contributions of the co-authors were not considered carefully. Two co-authors have little contributions, which cannot constitute any main contribution. It was a mistake when the first author forgot to update the actual authors, and he hurried to upload the incomplete and flaw file

ABORDAJE QUIRURGICO DEL QUISTE GLOBULOMAXILAR

Is defined and clasifiqued the Globular Cyst of Maxillary, indicating the controversy about your etiology and describe the thecnics for the surgical treatment. Finally to introduce a clinical case. Your treatment is realiced in the Nationald University of San Marcos School of Dentistry Department ofthe Oral and Facial Maxillary Surgery, in Lima•Perú.Se define y clasifica el quiste globulomáxilar; indicándose las controversias actuales sobre su etiología y se describen las técnicas para su abordaje quirúrgico. Finalmente se presenta un caso clínico tratado en el Servicio de Cirugía Bucal y Maxilo Facial

FACTORES CONTEXTUALES IDENTIFICADOS EN LAS DECISIONES FINANCIERAS EN LA RELACIÓN DE PAREJA

The present study aimed to describe the contextual characteristics present in financial decisions (money management) in the couple relationship, 63 men and 50 women, between18 and 48 (M= 22.12; SD=5) years of age, from Queretaro, Mexico. They were selected through non-probability convenience sampling. To explore the contextual characteristics offinancial decisions in the couple, an open question was asked to obtain their descriptions. The analysis of results yielded categories named as affection, socioculture, economy andfinance, collaboration and gender equity, which demonstrate behaviors present in the couple, differentiated for men and women. The results describe a higher frequency indecisions based on socioculture and economic income as the main categories in the management of money in the couple. It is men who report these two categories with greaterrelevance, while women attach importance to collaboration in financial interaction within the relationship. Finally, the usefulness of the results related to socioculture and itsrelationship with money management within the couple´s dynamics is discussed, as well as its continuity for future research in financial psycholog

Equilibrium susceptibilities of superparamagnets: longitudinal & transverse, quantum & classical

The equilibrium susceptibility of uniaxial paramagnets is studied in a unified framework which permits to connect traditional results of the theory of quantum paramagnets, \Sm=1/2, 1, 3/2, ..., with molecular magnetic clusters, \Sm\sim5, 10, 20, all the way up, \Sm=30, 50, 100,... to the theory of classical superparamagnets. This is done using standard tools of quantum statistical mechanics and linear response theory (the Kubo correlator formalism). Several features of the temperature dependence of the susceptibility curves (crossovers, peaks, deviations from Curie law) are studied and their scalings with \Sm identified and characterized. Both the longitudinal and transverse susceptibilities are discussed, as well as the response of the ensemble with anisotropy axes oriented at random. For the latter case a simple approximate formula is derived too, and its range of validity assessed, so it could be used in modelization of experiments.Comment: 32 pages, 5 figures. Submitted to J.Phys.Condens.Matte

High temperature optical absorption investigation into the electronic transitions in sol–gel derived C12A7 thin films

Optical absorption into 6 mm thick sol–gel derived films, annealed at 1300 °C of 12CaO·7Al2O3 calcium aluminate binary compound on MgO〈100〉 single crystal substrates was studied at temperatures ranging from room temperature to 300 °C. Experimental data were analysed in both Tauc and Urbach regions. The optical band gap decreased from 4.088 eV at 25 °C to 4.051 eV at 300 °C, while Urbach energy increased from 0.191 eV at 25 °C to 0.257 eV at 300 °C. The relationship between the optical band gap and the Urbach energy at different temperatures showed an almost linear relationship from which the theoretical values of 4.156 and 0.065 eV were evaluated for the band gap energy and Urbach energy of a 12CaO·7Al2O3 crystal with zero structural disorder at 0 K

Nonlinear Aeroelastic Framework Based on Vortex-Lattice Method and Corotational Shell Finite Element

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97077/1/AIAA2012-1976.pd

Spin interactions and switching in vertically tunnel-coupled quantum dots

We determine the spin exchange coupling J between two electrons located in two vertically tunnel-coupled quantum dots, and its variation when magnetic (B) and electric (E) fields (both in-plane and perpendicular) are applied. We predict a strong decrease of J as the in-plane B field is increased, mainly due to orbital compression. Combined with the Zeeman splitting, this leads to a singlet-triplet crossing, which can be observed as a pronounced jump in the magnetization at in-plane fields of a few Tesla, and perpendicular fields of the order of 10 Tesla for typical self-assembled dots. We use harmonic potentials to model the confining of electrons, and calculate the exchange J using the Heitler-London and Hund-Mulliken technique, including the long-range Coulomb interaction. With our results we provide experimental criteria for the distinction of singlet and triplet states and therefore for microscopic spin measurements. In the case where dots of different sizes are coupled, we present a simple method to switch on and off the spin coupling with exponential sensitivity using an in-plane electric field. Switching the spin coupling is essential for quantum computation using electronic spins as qubits.Comment: 13 pages, 9 figure

Plasmon Modes and Correlation Functions in Quantum Wires and Hall Bars

We present microscopic derivations of the one-dimensional low-energy boson effective Hamiltonians of quantum wire and quantum Hall bar systems. The quantum Hall system is distinguished by its spatial separation of oppositely directed electrons. We discuss qualitative differences in the plasmon collective mode dispersions and the ground state correlation functions of the two systems which are consequences of this difference. The slowly-decaying quasi-solid correlations expected in a quantum wire are strongly suppressed in quantum Hall bar systems.Comment: 7 pages, RevTex, 3 figures and 1 table included; references updated and minor typos correcte