Defense: Magneto-Elastic Dynamics in Nanomagnetic Metamaterials

Speaker Name: 
Cassidy Berk
Speaker Title: 
PhD Candidate (Advisor: Holger Schmidt)
Speaker Organization: 
Electrical Engineering
Start Time: 
Thursday, April 18, 2019 - 10:30am
End Time: 
Thursday, April 18, 2019 - 12:30pm
Location: 
Engineering 2, Room 475
Organizer: 
Holger Schmidt

Abstract:  5000 years ago cuneiform was imprinted on clay tablets in order to store information in Mesopotamia. The necessity to store information was due to the increasing complexity of civilizations which evolved after the Neolithic revolution. Today magnetic materials are used in order to imprint 0’s and 1’s into the spins of electrons. Again, this level of technological prowess is a reflection of our growing complexity as a civilization. Currently, we are in the throes of an information revolution, where individuals, businesses and governments alike store every possible bit of data obtainable. The demands of processing this data faster as well as addressing the massive amount of energy required to store it is going to be a major technological challenge of the ensuing decades. Being one of the dominant means of storing information, it is necessary to explore different methods of manipulating the spins in magnetic materials. Utilizing ultrafast laser pulses enables us to probe the magnetic (magnon) system at unprecedentedly fast timescales (femtoseconds) and using the material’s elastic (phonon) degree of freedom may enable more energy efficient control of the spins. At the very least a more thorough understanding of the magnon-phonon interaction in condensed mater systems is important from a fundamental perspective. I utilize Time Resolved Magneto-Optical Kerr Effect Spectroscopy to characterize magnetic multilayer structures. I also present a novel all-optical method of manipulating the spin systems in these multilayers. Finally, I explore the coupling and hybridization of elastic and magnetic vibrations in technologically relevant nanomagnetic systems.