Foreword Special Issue on Spintronics - IEEE Xplore

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IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 54, NO. 5, MAY 2007

Foreword Special Issue on Spintronics

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HIS Special Issue is devoted to the broad area of spintronics, excluding the well-advanced and developed storage media. Spintronics, which is spun from spin electronics, involves the exploitation of spin degrees of freedom in solids. Spin has been used very successfully in magnetoelectronics, and the trend continues with new developments taking place at a rapid pace. Attempts are ongoing to utilize spin in the context of traditional electronic and optoelectronic devices. For that effort to be successful, efficient spin-polarized electron injection and long critical path length must be achieved before losing spin coherence. Potential advantages are nonvolatility, increased data processing speed, and decreased power consumption, to cite a few. Faster and less power-consuming transistors have been projected, albeit rather optimistically, because flipping the spin takes 10 to 50 times less power than charging a gate, and the associated transport could be many times faster than classical charge transport. For the successful incorporation of spin phenomena into existing semiconductor technology or technologies to follow, several technical issues such as efficient injection, transport, control and manipulation, and detection of spin polarization as well as spin-polarized currents must be resolved, and already, great strides have been made. In addition to magnetic metals, the novel magnetic semiconducting and metal–oxide materials possess interesting magnetic and electrical anisotropies and pronounced magnetoresistance effects, which should be beneficial for incorporation in many magnetic devices that are already in the market. The field is now at a critical juncture in that device results are becoming available. Therefore, this Special Issue attempts to bring recent developments to the attention of the device community. The invited overall review of the field by Flatté makes a very good segue into the other very important topics discussed in invited papers by internationally renowned experts as follows: Semiconductors Between Spin-Polarized Sources and Drains by Fert et al.; Spin Injection and Detection in Semiconductors—Electrical Issues and Device Aspects by Van Roy et al.; Ferromagnetic Semiconductor Heterostructures for Spintronics by Dietl et al.; Electrical Manipulation of Spin Precession in an InGaAsBased 2DEG Due to the Rashba Spin-Orbit Interaction by Nitta and Bergsten; MOS- Based Spin Devices for Reconﬁgurable Logic by Tanaka and Sugahara;

Digital Object Identifier 10.1109/TED.2007.895274

Tunneling Anisotropic Magnetoresistance-Based Devices by Gould et al.; Spin-Polarized Transport in II–VI Magnetic ResonantTunneling Devices by Sánchez et al.; Magnetic Tunnel Junctions for Spintronic Memory and Beyond by Ikeda et al.; Oxide Spintronics by Bibes and Barthélémy. In addition, lateral spin valves are discussed in a paper by Johnson, spin manipulation by Enaya et al., and issues with magnetic ion-doped ZnO by Pearton et al. The guest editors would like to extend their sincere thanks to the Editor-in-Chief of the IEEE TRANSACTIONS ON ELECTRON DEVICES, Dr. D. Verret, for his counsel and leadership, and to J. Marsh in the Electron Devices Society Office for handling the manuscripts and making sure that the guest editors stayed focused. Last but not least, the team would like to express its deepest appreciation to the reviewers for their time and effort that certainly helped maintain a healthy discourse as well as improving the quality of the papers.

LAURENS W. MOLENKAMP, Guest Editor EPIII, Am Hubland Physikalisches Institut der Universitaet Wuerzburg D-97074 Wuerzburg, Germany [email protected] JAGADEESH S. MOODERA, Guest Editor Francis Bitter Magnet Laboratory Massachusetts Institute of Technology Cambridge, MA 02139 USA [email protected] HADIS MORKOÇ, Guest Editor Virginia Commonwealth University Richmond, VA 23284-3072 USA [email protected] HIDEO OHNO, Guest Editor Tohoku University Research Institute for Electrical Communication Sendai 980-8577, Japan [email protected] RAMAMOORTHY RAMESH, Guest Editor Department of Materials Science and Engineering and Department of Physics University of California Berkeley Berkeley, CA 94720-1760 USA [email protected]

0018-9383/$25.00 © 2007 IEEE


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Laurens W. Molenkamp was a Professor of Experimental Physics (C3) at RWTH, Aachen, Germany, in 1994. He moved to the Physikalisches Institut der Universitaet Wuerzburg, Wuerzburg, Germany, in April 1999, as the Chair of Experimental Physics (EPIII), where he continues research in spintronics and spin-related phenomena. His background includes optical and quantum transport studies in semiconductor nanostructures and spintronics.

Jagadeesh S. Moodera received the Ph.D. degree from the Indian Institute of Technology, Madras, India. He is currently a Senior Research Scientist in the Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, and the Leader of the Thin Film Magnetism, Tunneling, and Nano Spintronics Group. He has also been a Visiting Professor in the Department of Physics, Eindhoven Technical University, Eindhoven, The Netherlands, since 1999. He is also a Collaborator of the National Nanospintronics Program with the Korea Institute of Science and Technology, Seoul, Korea, and a member of the Advisory/Review Board for the National Nanospins Program in The Netherlands. He pioneered the study of ferromagnet–insulator–ferromagnet tunnel junctions, which are the basis for the magnetic random access memory and future magnetoelectronic logic elements. He extensively contributed to the spin-polarized tunneling of half-metallic ferromagnets, spin-filter and exchange effects in tunnel junctions with magnetic barriers, and superconductive electronics studies of MgB2 superconductor including Josephson junctions. He has published many review articles, three book chapters, and more than 125 papers in different journals. He has presented more than 150 invited talks and colloquia at national and international conferences, universities, and companies in 14 different countries. He also had research collaborations with many well-known research groups in the USA and abroad, and is the holder of two international patents. His research interests include fundamental phenomena in magnetism, particularly, spin-polarized tunneling, superconductivity, and nanospintronics. Dr. Moodera is a Fellow of the American Physical Society. He is an Executive Member of the Topical Group on Magnetism of the American Physical Society, an Advisory Committee Member of the Magnetism and Magnetic Materials Conference, a member of the Editorial Board of the Journal of Magnetics (Korea), and an Advisory Board Member in several international conferences. In 2006, he was the Elected Chairman of the Gordon Research Conference on Magnetic Nanostructures. He is a recipient of the IBM Research Award (1995–1997) and the TDK Research Award (1999 and 2000).

Hadis Morkoç received the B.S.E.E. and M.S.E.E. degrees from Istanbul Technical University, Istanbul, Turkey, and the Ph.D. degree in electrical engineering from Cornell University, Ithaca, NY. From 1976 to 1978, he was with Varian Associates, Palo Alto, CA, where he was involved in various novel FET structures and optical emitters based on then new semiconductor heterostructures. He held visiting positions at the AT&T Bell Laboratories (1978–1979), the California Institute of Technology, Pasadena, and Jet Propulsion Laboratory (1987–1988), and the Air Force Research Laboratories-Wright Patterson AFB as a University Resident Research Professor (1995–1997). From 1978 to 1997, he was with the University of Illinois, Urbana. In 1997, he joined the newly established School of Engineering, Virginia Commonwealth University, Richmond. He and his group members have been responsible for a number of advancements in compound semiconductor, including wide-bandgap nitride, heterostructures, and devices. He has been a prolific writer with a number of books, review and tutorial papers, book chapters, and journal publications. He is among the most cited in the fields of engineering, physics, and materials science. Dr. Morkoç is a Fellow of the American Association for the Advancement of Science, a Life Fellow of the American Physical Society, a member of the Material Research Society, a member of the Optical Society of America, a member of Sigma Pi Sigma and Eta Kappa Nu, and a Life Member of Sigma Xi and Phi Kappa Phi. He is listed in Who’s Who in America, Who’s Who in the Midwest, American Men and Women in Science, Who’s Who in Engineering, and International Men of Achievement.

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Hideo Ohno received the B.S., M.S., and Ph.D. degrees from the University of Tokyo, Tokyo, Japan, in 1977, 1979, and 1982, respectively. In 1979, he spent one year as a Visiting Graduate Student at Cornell University, Ithaca, NY. In 1982, he joined the Faculty of Engineering, Hokkaido University, Sapporo, Japan. From 1988 to 1990, he was a Visiting Scientist at the IBM T. J. Watson Research Center. In 1994, he joined Tohoku University, Sendai, Japan, as a Professor, where he is currently the Director of the Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication. He is heading an IT program on the “Development of Universal Low-Power Spin Memory,” which is funded by MEXT, and is also the Research Director of the Semiconductor Spintronics Project, Exploratory Research for Advanced Technology, Japan Science and Technology Agency. He has authored or coauthored more than 280 journal papers that cover the areas from compound semiconductor materials and devices to nonmagnetic semiconductors, ferromagnetic semiconductors, and metal spintronics. His current research interests include physics and applications of spin-related phenomena in semiconductor as well as in metal-based nanostructures. Dr. Ohno has been a Fellow of the Institute of Physics since 2004. He currently serves on the editorial board of several international journals including the Virtual Journal of Nanoscale Science and Technology, Solid State Communications, and Semiconductor Science and Technology. He is a recipient of the IBM Japan Science Award (1998), the IUPAP Magnetism Prize (2003), Japan Academy Prize (2005), and the 2005 Agilent Technologies Europhysics Prize. Ramamoorthy Ramesh received the Ph.D. degree from the University of California at Berkeley in 1987. From 1987 to 1988, he was a Staff Scientist at the Lawrence Berkeley Laboratory, where he carried out pioneering research on high-temperature superconductors and codiscovered the 110-K superconducting phase in the bismuth cuprate system. From 1989 to 1995, he was with Bellcore, where he initiated research in several key areas, including ferroelectric nonvolatile memories. His landmark contributions in ferroelectrics came through the recognition that conducting oxide electrodes are the solution to the problem of polarization fatigue, which for 30 years, remained an enigma and unsolved problem. This contribution is now recognized worldwide with many industrial and research laboratories implementing such an approach. In 1994, in collaboration with S. Jin (Lucent Technologies), he initiated research on manganite thin films, and they coined the term colossal magnetoresistive (CMR) oxides; their paper in Science is the fourth highest cited paper, with more than 2000 citations. In 1995, he joined the University of Maryland, College Park, where he became a Professor in 1999 and a Distinguished University Professor in 2003. He is currently a Professor at the Department of Materials Science and Engineering and the Department of Physics, University of California at Berkeley, where he continues to pursue key scientific and technological problems in complex multifunctional oxide thin films, nanostructures, and heterostructures. His recent work has pioneered the resurgence of research activity in multifunctional materials. His group demonstrated the existence of a large ferroelectric polarization in multiferroic BiFeO3 films (Science, 2003), in agreement with first principle predictions. His group has also demonstrated a very novel approach to create self-assembled multiferroic nanostructures. This work (Science, 2004) demonstrated, through a 3-D heteroepitaxy, the formation of multifunctional ferroelectric-magnetic nanostructures with strong lattice coupling due to heteroepitaxy. His work in the areas of materials physics of complex oxide thin films and heterostructures, is recognized worldwide. He has more than 350 publications. He is the holder of 18 issued and 11 pending patents. His research is extensively cited (more than 14 000 citations, putting him among one of the most the highly cited researchers in physics). In 2000, he was awarded the Outstanding Achievement Award from the International Symposium on Integrated Ferroelectrics. He received the Humboldt Senior Scientist Prize from the Alexander von Humboldt Foundation for his pioneering work on the fundamental nanoscale science of size scaling in ferroelectric thin films, the A. James Clark College of Engineering Faculty Outstanding Research Award and Fellowship to the American Physical Society (2001) as well as the 2005 Adler Lectureship of the American Physical Society. In 2006, he was awarded the Ikeda Lectureship in Japan, the Brahm Prakash visiting chair at the Indian Institute of Science.