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

Signatures of dynamically polarized nuclear spins in all-electrical lateral spin transport devices

The effect of nuclear spins in Fe/GaAs all-electrical spin-injection devices is investigated. At temperatures below 50 K, strong modifications of the non-local spin signal are found that are characteristic for hyperfine coupling between conduction electrons and dynamically polarized nuclear spins. The perpendicular component of the nuclear Overhauser field depolarizes electron spins near zero in-plane external magnetic field, and can suppress such dephasing when antialigned with the external field, leading to satellite peaks in a Hanle measurement. The features observed agree well with a Monte Carlo simulation of the spin diffusion equation including hyperfine interaction, and are used to study the nuclear spin dynamics and relate it to the spin polarization of injected electrons.Comment: 6 pages, 4 figure

Literary Needle Drops: The Use of Music as a Postmodern Tool in Contemporary Fiction

An examination of musical references (“literary needle drops”) in contemporary literature: Jennifer Egan’s A Visit from the Goon Squad, Zadie Smith’s On Beauty, and Haruki Murakami’s Colorless Tsukuru Tazaki and His Years of Pilgrimage. The novels are viewed through the various conceptual lens, literary and otherwise, such as Marcel Danesi’s Modal Flow Principle or “perceptual stimulations” as defined by Guillemette Bolens. Egan’s novel utilizes punk bands and tracks to construct her characters’ identities, and send them on a journey through lost time to reflect on who they once were, who they have become, and whether they have been able to preserve the authenticity the Bay area music scene once demanded of them. Smith transforms the genre of hip-hop into an authentic Black cultural proxy in order to juxtapose the artform with classical music, which is largely propelled by a lily-White discourse. Lastly, Murakami creates a work with a carefully curated selection of jazz and classical pieces, as well as pop songs, to enrich the narrative through added characterization and the establishing of mood

Temperature dependence of the nonlocal voltage in an Fe/GaAs electrical spin injection device

The nonlocal spin resistance is measured as a function of temperature in a Fe/GaAs spin-injection device. For nonannealed samples that show minority-spin injection, the spin resistance is observed up to room temperature and decays exponentially with temperature at a rate of 0.018\,K$^{-1}$. Post-growth annealing at 440\,K increases the spin signal at low temperatures, but the decay rate also increases to 0.030\,K$^{-1}$. From measurements of the diffusion constant and the spin lifetime in the GaAs channel, we conclude that sample annealing modifies the temperature dependence of the spin transfer efficiency at injection and detection contacts. Surprisingly, the spin transfer efficiency increases in samples that exhibit minority-spin injection.Comment: 10 pages, 4 figure

Reduced-order models of the Martian atmospheric dynamics

In this paper we explore the possibility of deriving low-dimensional models of the dynamics of the Martian atmosphere. The analysis consists of a Proper Orthogonal Decomposition (POD) of the atmospheric streamfunction after first decomposing the vertical structure with a set of eigenmodes. The vertical modes were obtained from the quasi-geostrophic vertical structure equation. The empirical orthogonal functions (EOFs) were optimized to represent the atmospheric total energy. The total energy was used as the criterion to retain those modes with large energy content and discard the rest. The principal components (PCs) were analysed by means of Fourier analysis, so that the dominant frequencies could be identified. It was possible to observe the strong influence of the diurnal cycle and to identify the motion and vacillation of baroclinic waves