827 research outputs found
Spin injection and spin accumulation in permalloy-copper mesoscopic spin valves
We study the electrical injection and detection of spin currents in a lateral
spin valve device, using permalloy (Py) as ferromagnetic injecting and
detecting electrodes and copper (Cu) as non-magnetic metal. Our multi-terminal
geometry allows us to experimentally distinguish different magneto resistance
signals, being 1) the spin valve effect, 2) the anomalous magneto resistance
(AMR) effect and 3) Hall effects. We find that the AMR contribution of the Py
contacts can be much bigger than the amplitude of the spin valve effect, making
it impossible to observe the spin valve effect in a 'conventional' measurement
geometry. However, these 'contact' magneto resistance signals can be used to
monitor the magnetization reversal process, making it possible to determine the
magnetic switching fields of the Py contacts of the spin valve device. In a
'non local' spin valve measurement we are able to completely isolate the spin
valve signal and observe clear spin accumulation signals at T=4.2 K as well as
at room temperature. We obtain spin diffusion lengths in copper of 1 micrometer
and 350 nm at T=4.2 K and room temperature respectively.Comment: 8 pages (incl. figures), 7 figures, RevTex, conferenc
Implicit social learning in relation to autistic-like traits.
We investigated if variation in autistic traits in the typically-developed population (using the Autism-spectrum Quotient, AQ) influenced implicit learning of social information. In the learning phase, participants repeatedly observed two identities whose gaze and expression conveyed either a pro- or antisocial disposition. These identities were then employed in a gaze-cueing paradigm. Participants made speeded responses to a peripheral target that was spatially pre-cued by a non-predictive gaze direction. The low AQ group (n = 50) showed a smaller gaze-cueing effect for the antisocial than for the prosocial identity. The high AQ group (n = 48) showed equivalent gaze-cueing for both identities. Others' intentions/dispositions can be learned implicitly and affect subsequent responses to their behavior. This ability is impaired with increasing levels of autistic traits
Modality-specific Affective Responses and their Implications for Affective BCI
Reliable applications of multimodal affective brain-computer interfaces (aBCI) require a detailed understanding of the processes involved in emotions. To explore the modality-specific nature of affective responses, we studied neurophysiological responses of 24 subjects during visual, auditory, and audiovisual affect stimulation and obtained their subjective ratings. Coherent with literature, we found modality-specific responses in the EEG: parietal alpha power decreases during visual stimulation and increases during auditory stimulation, whereas more anterior alpha power decreases during auditory stimulation and increases during visual stimulation. We discuss the implications of these results for multimodal aBCI
Highly efficient room temperature spin injection in a metal-insulator-semiconductor light emitting diode
We demonstrate highly efficient spin injection at low and room temperature in
an AlGaAs/GaAs semiconductor heterostructure from a CoFe/AlOx tunnel spin
injector. We use a double-step oxide deposition for the fabrication of a
pinhole-free AlOx tunnel barrier. The measurements of the circular polarization
of the electroluminescence in the Oblique Hanle Effect geometry reveal injected
spin polarizations of at least 24% at 80K and 12% at room temperature
Brain computer interfaces as intelligent sensors for enhancing human-computer interaction
BCIs are traditionally conceived as a way to control apparatus, an interface that allows you to act on" external devices as a form of input control. We propose an alternative use of BCIs, that of monitoring users as an additional intelligent sensor to enrich traditional means of interaction. This vision is what we consider to be a grand challenge in the field of multimodal interaction. In this article, this challenge is introduced, related to existing work, and illustrated using some best practices and the contributions it has received
Історичне краєзнавство як складова національної освіти: теоретичний аспект
Аналізується процес утвердження історичного краєзнавства в системі національної освіти. Розглядаються теоретичні питання про предмет, об’єкт і завдання історичного краєзнавства. Акцентується увага на виховній і консолідуючій функції історичного краєзнавства в процесі відродження української нації.Анализируется процесс становления исторического краеведения в системе национального образования. Рассматриваются теоретические вопросы о предмете, объекте и задачах исторического краеведения. Внимание акцентируется на воспитательной и консолидирующей функциях исторического краеведения в процессе возрождения украинской нации.The processes of the formation of the local history studies in the system of the national education had been analyzed. The theoretical aspects of the objects and tasks of the local history studies had been shown. The educational and consolidation functions of the local history studies in the Ukrainian national resurrection process had been pointed
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