Sadamichi Maekawa is the Director of Advanced Science Research Center, Japan Atomic Energy Agency. He received his PhD degree from Tohoku University. He was a Post Doctoral Fellow at IBM Watson Research Center, Professor at Nagoya University and Tohoku University. He has been awarded a 2001, the title of Honda Professor in 2005, a Fellow of the American Physical Society in 2007, and the title of the Distinguished Professor in 2008. His main research topics are solid state theory including theory of electronic properties in strongly correlated electron systems and theory of transport in magnetic nanostructures.Sergio O. Valenzuela is a Research Professor at ICN, Technology and a leader of the physics and Engineering of nanoelectronic devices group at the Centre d'Investigacions en Nanociència i Nanotecnologia (CSIC-ICN) since 2008. Prof. Valenzuela obtained his PhD in Physics at the University of Buenos Aires, Argentina, was a Postdoctoral Fellow and Research Associate at Harvard University and a Research Scientist at the Massachusetts Institute of Technology (MIT). He is recipient of the 2009 IUPAP Young Scientist prize in magnetism.Eiji Saitoh is a Professor at Institute for Materials Research, Tohoku University. He received his PhD degree from Tokyo University. He was an Assistant Professor and a Lecturer at Keio University. He has been awarded the Sir Martin Wood Prize in 2008, IUPAP Young Scientist Award in 2009, and Japan Academy Medal in 2011. His main research topics are experimental solid state physics including spintronics, electronic properties in strongly correlated electron systems and nanoscale magnetism.Takashi Kimura is a Professor at INAMORI Frontier Research Center, Kyushu University. He received his PhD degree from Osaka University in 2002. He was a Post Doctoral Fellow at Riken Frontier Research System and an assistant professor in Institute for Solid State Physics, University of Tokyo. He has received IUPAP young scientist medal on Magnetism, Young Scientists' Prize from MEXT and Young Scientist Award of the Physical Society of Japan. His current research topics are spin-related transports in nano-structured ferromagnetic/nonmagnetic hybrid structures and manipulations of magnetic domain structures in patterned ferromagnet.

This book provides the active researcher a state-of-the-art summary of the physics and applications of spin current. The end-of-chapter references are extremely current and as a result, the contents of this book are likely to be helpful and useful as a guide towards future research.

• PART I: SPIN CURRENT; PART II: SPIN HALL EFFECT; PART III: SPIN-TRANSFER TORQUE