题 目：Imaging Spin Dynamics in Magnetic Nanostructures
报告人：程雪梅副教授（Department of Physics, Bryn Mawr College）
Spintronics, an emerging technology that exploits electron spin and its associated magnetic moment as well as electron charge, is an exciting and challenging area of nanotechnology. Spintronic devices, combining the advantages of magnetic materials and semiconductors, are likely to be stable, fast and capable of non-volatile data storage as well as being energy-efficient. Magnetic nanostructures, a crucial element to spintronics, have been the subject of extensive studies. Direct imaging of the magnetic configuration and spin dynamics in these magnetic nanostructures is especially important to thedevelopment of Spintronics.
In this talk I will present imaging studies of the magnetic dynamics in nanostructured materials using two different methods: time-resolved photoemission electron microscopy and magneto-optical Kerr effect microscopy. Magnetic images obtained using these methods have provided critical information for understanding magnetic vortex dynamics in micron and sub-micron scaled magnetic disks and unusual antisymmetric magnetoresistance in Pt/Co/Pt trilayers with a confined straight domain wall.
Bio sketch of Xuemei Cheng
Xuemei Cheng received her bachelor’s degree in physics from Nanjing University in 1997, and her master’s degree in microelectronics and solid state electronics, also from Nanjing University in 2000. She continued her studies at the John Hopkins University where she earned masters and Ph.D. degrees in physics in 2004 and 2006, respectively. After a postdoctoral fellowship in the X-ray Science Division at Argonne National Laboratory, she joined the faculty at Bryn Mawr College in 2009.
Cheng’s research focuses on the fabrication, charaterization and application of nanoscales materials. Current projects include: templated electrochemical deposition of nanoscaled materials for energy and medical applications; time-resolved imaging of spin dynamics in magnetic nanostructures; and x-ray magnetic circular dichroism study of multiferroic materials. She has authored or coauthored 36 papers in peer-reviewed journals, including Science, Reports on Progress in Physics, Physical Review Letters, Physical Review B, and Applied Physics Letters. She has recently received an NSF CAREER award and an NSF MRI grant.