Olaf M. J. van 't Erve

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Topological insulators exhibit metallic surface states populated by massless Dirac fermions with spin-momentum locking, where the carrier spin lies in-plane, locked at right angles to the carrier momentum. Here, we show that a charge current produces a net spin polarization via spin-momentum locking in Bi2Se3 films, and this polarization is directly(More)
The use of carrier spin in semiconductors is a promising route towards new device functionality and performance. Ferromagnetic semiconductors (FMSs) are promising materials in this effort. An n-type FMS that can be epitaxially grown on a common device substrate is especially attractive. Here, we report electrical injection of spin-polarized electrons from(More)
The growing field of spintronics relies on new techniques and technologies for injecting and detecting electron spins to generate spin-dependent signals and utilize spin as a new state variable. Magnetic tunnel junctions (MTJs) do this by employing thin oxide layers as insulating barriers between two ferromagnetic metals, but the oxides suffer from defects(More)
The International Technology Roadmap for Semiconductors has identified the electron's spin angular momentum as a new state variable that should be explored as an alternative to the electron's charge for use beyond the size scaling of Moore's Law. A major obstacle has been achieving control of the spin variable at temperatures required for practical(More)
Spin manipulation in a semiconductor offers a new paradigm for device operation beyond Moore's law. Ferromagnetic metals are ideal contacts for spin injection and detection, but the intervening tunnel barrier required to accommodate the large difference in conductivity introduces defects, trapped charge and material interdiffusion, which severely compromise(More)
The coupled imperatives for reduced heat dissipation and power consumption in high-density electronics have rekindled interest in devices based on tunnelling. Such devices require mating dissimilar materials, raising issues of heteroepitaxy, layer uniformity, interface stability and electronic states that severely complicate fabrication and compromise(More)
Spin-based devices offer non-volatile, scalable, low power and reprogrammable functionality for emerging device technologies. Here we fabricate nanoscale spintronic devices with ferromagnetic metal/single-layer graphene tunnel barriers used to generate spin accumulation and spin currents in a silicon nanowire transport channel. We report the first(More)
We demonstrate that hydrogenated graphene performs as a homoepitaxial tunnel barrier on a graphene charge/spin channel. We examine the tunneling behavior through measuring the IV curves and zero bias resistance. We also fabricate hydrogenated graphene/graphene nonlocal spin valves and measure the spin lifetimes using the Hanle effect, with spintronic(More)
We demonstrate that information can be transmitted and processed with pure spin currents in silicon. Fe/Al<sub>2</sub>O<sub>3</sub> tunnel barrier contacts are used to produce significant electron spin polarization in the silicon, generating a spin current which flows outside of the charge current path. The spin orientation of this pure spin current is(More)
We have demonstrated the injection, modulation and detection of pure spin diffusion current in silicon in a lateral transport geometry compatible with existing device design, fabrication and scaling. This approach injects spin-polarized electrons near the silicon conduction band edge with near unity conversion efficiency and low bias voltages (&#x223C; 2(More)