The working principle

1. Spin-effect amplification in a three-terminal deviceH. Dery, L. Cywinski, L.J. Sham University California San Diego DMR-0325599 Source L drain R drain The working principle Spin current control. The magnetization direction of the left drain parallel (P) or antiparallel (AP) to the other two ferromagnets controls the spin currents between the source and the right drain with the aid of the two voltage sources. Nonvolatile memory. By making the AP current zero and the P current finite for the same voltages, we digitize the current to reflect the magnetic information of the left ferromagnet. “Soft layer” Device structure Each mesa is a Schottky junction of a ferromagnet spin polarizing the current in the paramagnetic semiconductor channel in either direction at room temperature. The spin currents in the channel are diffusive, driven by the spatial variation of the spin accumulation dependent on the magnetizations of the ferromagnet layers. Advantage Based on exisiting technology. Potential Basic component for magnetic computation. Interface with optical excitation for opto-spintronics. Preprint archive: cond-mat/0507378

2. Optical Control in Semiconductors for Spintronics and Quantum Information ProcessingL.J. Sham Univ California San Diego DMR-0325599 Societal Impact: The theory of control of electron spins is an important aspect of nanoscience with applications to technology. The proposed amplification device is a basic component of a new paradigm in integrating magnetic memory to electronic processers. Of pressing concern is the training of quantum engineers. I have a two-prong approach. By engineering and physics students and postdoc working together, each side learns from the other quantum mechanics or device function concepts. I am designing two new courses on application of quantum mechanics to spin engineering and have taught the introductory one. Education: Thomas Grange, REU last summer, studied the spin current transport, now at Ecole Normale Supérieur de Paris. Lukasz Cywinski, a Ph.D. student, is responsible for collaboration with Kono’s group on optical control of ferromagnetism in semiconductor and for the study of spin currents. Hanan Dery, a Ph.D. in E.E., works on design of spintronic devices. His work in the group is a prototype collaboration between physicists and engineers on spin device work. The dividend is the work above. Parin Dalel, a new graduate student with industrial experience and patents, educates the group on classical computers