Friday 23 Jan 2015: Magnonics: Trends and Challenges
Prof. Burkard Hillebrands - Technische Universitat Kaiserslautern
Newman Red 12:00-13:00
With the fast growth in the volume of information being processed, researchers are charged with the primary task of finding new ways for fast and efficient processing and transfer of data. Spin excitations - spin waves and their quanta magnons - open up a very promising branch of high-speed and low-power information processing. In contrast to conventional spintronics, which relies on the transport of spin-polarized electron currents, magnon currents are spin fluxes, which propagate entirely without charge transfer through magnetically, ordered conducting and insulating materials. Moreover, the rich physics of magnon dynamics in micro and nanoscale magnetic systems opens doors to a wide range of data processing functionalities.
There are two main directions to be developed. The first one is a realization of new functionalities and devices based on the available "magnonic tool-box". The second one is to use fundamentally new collective phenomena such as Bose-Einstein condensates (BEC) for novel applications such as information processing.
I will give an overview over the current trends in the field and will address specific challenges. An extraordinary challenge is the use of macroscopic quantum phenomena such as magnon Bose-Einstein condensates (BEC). In a classic condensate, the group velocity is zero. Recently we have succeeded to create BEC with non-zero group velocity by spin-orbit coupling to phononic states, allowing for transfer of information via local BEC states. Even more promising is the use of magnon supercurrents driven by a phase gradient in the magnon BEC. A second challenge is to control magnon currents by other magnons - the realization of a magnon transistor. I will report about the successful realization and application of this device.