Comprehension of wh-questions in a case of mixed dementia

We investigated processing of wh-questions and declarative sentences with differing syntactic complexity in a case of mixed dementia (FA). FA was impaired in her ability to understand syntactically complex declarative sentences and syntactically complex wh-questions beginning with which but not complex who questions. This profile, novel in dementia, is similar to that reported for people with agrammatic aphasia and discerns a ‘‘fault line’’ of the language system along a syntactic/semantic paramete

Interferometric detection of spin-polarized transport in the depletion layer of a metal-GaAs Schottky barrier

It is shown that the Kerr rotation of spin-polarized electrons is modulated by the distance of the electrons from the sample surface. Time-resolved Kerr rotation of optically-excited spin-polarized electrons in the depletion layer of n-doped GaAs displays fast oscillations that originate from an interference between the light reflected from the semiconductor surface and from the front of the electron distribution moving into the semiconductor. Using this effect, the dynamics of the photogenerated charge carriers in the depletion layer of the biased Schottky barrier is measured.Comment: 10 pages, 4 figure

An introduction to Encoded Archival Description

pp. 47-6

Mode Spectroscopy and Level Coupling in Ballistic Electron Waveguides

A tunable quantum point contact with modes occupied in both transverse directions is studied by magnetotransport experiments. We use conductance quantization of the one-dimensional subbands as a tool to determine the mode spectrum. A magnetic field applied along the direction of the current flow couples the modes. This can be described by an extension of the Darwin-Fock model. Anticrossings are observed as a function of the magnetic field, but not for zero field or perpendicular field directions, indicating coupling of the subbands due to nonparabolicity in the electrical confinement.Comment: 4 pages, 3 figure

The Grover algorithm with large nuclear spins in semiconductors

We show a possible way to implement the Grover algorithm in large nuclear spins 1/2<I<9/2 in semiconductors. The Grover sequence is performed by means of multiphoton transitions that distribute the spin amplitude between the nuclear spin states. They are distinguishable due to the quadrupolar splitting, which makes the nuclear spin levels non-equidistant. We introduce a generalized rotating frame for an effective Hamiltonian that governs the non-perturbative time evolution of the nuclear spin states for arbitrary spin lengths I. The larger the quadrupolar splitting, the better the agreement between our approximative method using the generalized rotating frame and exact numerical calculations.Comment: 11 pages, 18 EPS figures, REVTe

Adiabatic quantum simulations with driven superconducting qubits

We propose a quantum simulator based on driven superconducting qubits where the interactions are generated parametrically by a polychromatic magnetic flux modulation of a tunable bus element. Using a time-dependent Schrieffer-Wolff transformation, we analytically derive a multi-qubit Hamiltonian which features independently tunable $XX$ and $YY$-type interactions as well as local bias fields over a large parameter range. We demonstrate the adiabatic simulation of the ground state of a hydrogen molecule using two superconducting qubits and one tunable bus element. The time required to reach chemical accuracy lies in the few microsecond range and therefore could be implemented on currently available superconducting circuits. Further applications of this technique may also be found in the simulation of interacting spin systems.Comment: 11 pages, 6 figure

Effect of exchange interaction on fidelity of quantum state transfer from a photon qubit to an electron-spin qubit

We analyzed the fidelity of the quantum state transfer (QST) from a photon-polarization qubit to an electron-spin-polarization qubit in a semiconductor quantum dot, with special attention to the exchange interaction between the electron and the simultaneously created hole. In order to realize a high-fidelity QST we had to separate the electron and hole as soon as possible, since the electron-hole exchange interaction modifies the orientation of the electron spin. Thus, we propose a double-dot structure to separate the electron and hole quickly, and show that the fidelity of the QST can reach as high as 0.996 if the resonant tunneling condition is satisfied.Comment: 5 pages, 4 figures, to be published in Phys. Rev. B Rapid Communication

Fitossociologia de um campo cerrado no Pantanal da Nhecolândia, Corumbá, MS.

Os campos cerrados há muito tempo vêm sendo ocupados para a criação extensiva de gado bovino no Pantanal de Mato Grosso do Sul. Apesar da grande importância dessa fisionomia para a pecuária na região, ainda são poucos os estudos de estrutura e composição florística nesse tipo de fisionomia. Desse modo, este trabalho teve como objetivo realizar um levantamento florístico e fitossociológico das espécies lenhosas de uma área de campo cerrado na fazenda Nhumirim, sub-região da Nhecolândia. As amostragens da vegetação foram feitas pelo método de quadrantes móveis, sendo incluídos somente indivíduos com diâmetro ao nível do solo (DAS) &#8805; 1 cm. Os parâmetros fitossociológicos foram estimados com auxílio do programa FITOPAC 1, além das similaridades florística (Índice de Jaccard) e proporcional da área. Registrou-se 187 indivíduos pertencentes a 23 espécies, 22 gêneros e 17 famílias. A densidade total foi de 1.670 indivíduos/hectare. A altura média dos indivíduos foi de 1,6 m, com amplitude de 0,4 m a 7,5 m. As espécies com maior Índice Valor de Importância e número de indivíduos foram Annona dioica, Byrsonima cydoniifolia e Mouriri elliptica (81, 39 e 13 indivíduos, respectivamente). A área estudada apresentou um baixo índice de similaridade florística quando comparada com as áreas de campo cerrado nas sub-regiões de Poconé e Paiaguás no Pantanal (MS e MT, respectivamente). No entanto, a similaridade proporcional foi maior, evidenciando semelhança na estrutura das formações vegetais comparadas, três das cinco áreas comparadas apresentaram índices acima de 30%, sendo Byrsonima cydoniifolia a principal espécie que contribuiu para a essa similaridade. Tanto no Paraná como em São Paulo os valores para ambos os índices foram mais baixos do que os encontrados na comparação com as sub-regiões do Pantanal. Na área de campo cerrado estudada Annona dioica, Byrsonima cydoniifolia, Mouriri elliptica foram as espécies mais importantes, sendo a área considerada pobre em relação à riqueza de espécies quando comparada com outras áreas de campo cerrado.bitstream/item/76172/1/BP119.pd