Cascading scheme for logic propagation

1. Theory of spin-based logic gates and circuitsH. Dery, L. Cywinski, P. Dalal, and L. J. Sham, University of California San Diego, DMR-0325599 A universal reprogrammable magneto-logic gate Electronics uses electron charges for the bit (basic unit of information). Spintronics adds electron spins as an additional bit with the possibility of increasing not only information capacity but also functionalities. This group developed a theory of spin current flow in a semiconductor laterally under ferromagnetic leads, showing how the memory function of the lead can be integrated with the currents in electronics for processing. Using the materials with properties already demonstrated by experiment, we designed an amplifier of measurable spin effects, a polarimeter for light, a universal magneto-logic gate, and a circuit of spin logic gates. By the principle of nonlocal output, the devices circumvent the weakness of semiconductor based spin valves and show the potential of integration of memory and processing, economy of power consumption and hardware, compared with the current CMOS technology. Cascading scheme for logic propagation

2. Optical Control in Semiconductors for Spintronics and Quantum Information ProcessingL. J. Sham, University of California San Diego, DMR-0325599 Societal Impact: Spin control is a basic quantum physics problem. Its application to spintronics requires close collaboration between physicists and engineers and the complement of their disciplines, both happening in this group. The short-range impact is the training of students and postdocs ready for the challenge of spin, nano and quantum engineering. The long-range impact is a teaching paradigm and the expectation that our theory and designs, be them successes or failures, will stimulate research and industrial development of spintronics to meet the criteria for a competing technology with the current dominant electronics technology. The societal benefits would be enormous. Education: 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 of collaboration between physicists and engineers on spin device work. Parin Dalal, a Ph.D. student with industrial experience and patents, is using information science to assess the information capacity of ensemble and single spins for spintronics and quantum information processing. He is invaluable in our device design.