Advances in Nonlinear Spin Waves – Bright Solitons from Repulsive Waves, Dark Soliton Pairs, and Foldover
Mingzhong Wu
Department of Physics, Colorado State University
Date and time:
Tuesday, November 17, 2015 - 4:00pm
Location:
ECOT 226
Abstract:
Spin waves in magnetic thin films provide a powerful and versatile test bed for the study of dynamics of nonlinear waves. In this presentation I will report on four of our recent studies on nonlinear spin waves in Y3Fe5O12 (YIG) thin films. I will first report the use of surface spin waves in YIG films to demonstrate for the first time the opposite phase jumps of dark soliton pairs. This phase property is expected theoretically but has never been demonstrated experimentally before. Then, I will report on the formation of bright envelope solitons from surface spin wave packets. Such soliton formation is surprising because bright solitons are usually expected for waves with an attractive nonlinearity, while surface spin waves exhibit a repulsive nonlinearity. In the third part, I will demonstrate the use of the soliton effect of nonlinear forward volume spin waves to realize a microwave pulse compulsion device. Finally, I will report a foldover effect for nonlinear forward volume spin waves in a YIG-based feedback ring system.
Biography: Mingzhong Wu received his Ph.D. in Solid State Electronics from Huazhong University of Science and Technology in 1999, joined the faculty of Colorado State University (CSU) in 2007, and is currently an Associate Professor of Physics at CSU. He is interested in many research topics in magnetics. His current research areas include magnetization dynamics, spintronics, nonlinear spin waves, thin film growth, and microwave magnetic materials and devices. He has authored/coauthored about 110 publications. Recently he has also co-edited a book on magnetic insulators (392 pages). He is currently serving as the Financial Chair of the IEEE Magnetics Society and an Associate Editor for IEEE Magnetics Letters.