Name of the speaker: Xianfan Xu
Organization: Purdue University
Nationality: USA


The Title of Speech: Nanoscale engineering for next generation data storage technology
Biography of the Speaker: Xianfan Xu is James J. and Carol L. Shuttleworth Professor of Mechanical Engineering at Purdue University with a courtesy appointment in Electrical and Computer Engineering at Purdue University. He obtained his B.Eng. degree in Engineering Thermophysics from the University of Science and Technology of China (1989), and M.S. (1991) and Ph.D. (1994) degrees in Mechanical Engineering from the University of California, Berkeley. His current research is focused on ultrafast and nanoscale optics and their applications in energy transfer/conversion studies, radiation, and nano-manufacturing. He is the recipient of the National Science Foundation Faculty CAREER Award and the Office of Naval Research Young Investigator Award, and is the recipient of GM Faculty Fellowship, B.F.S. Schaefer Young Faculty Award, Discovery in Mechanical Engineering Award, and the American Society of Mechanical Engineers Heat Transfer Memorial Award. He was elected Fellow of the American Society of Mechanical Engineers in 2006 and Fellow of SPIE in 2009.
Abstract of Speech: One of the very promising applications of nanotechnology is in the area of data storage. An areal density of 1 Tb/in2 is estimated to be the limit for the present hard disk drives (HDD) using perpendicular magnetic recording, due to the requirement of thermal stability and available magnetic write fields. Heat-assisted magnetic recording (HAMR) has the potential to keep increasing the areal density in the next generation HDDs by including a nanoscale optical antenna, called near field transducer (NFT) to locally and temporally heat a sub-diffraction-limited region in the recording medium above its Curie temperature to reduce the magnetic coercivity. This allows maintaining data thermal stability with use of very small grain in the medium. The NFTs are made of plasmonic nanoscale optical antenna to provide the capability of sub-wavelength light manipulation at optical and near-IR frequencies. These antennas are designed using both plasmonic resonance and localized plasmons to produce an enhance field within an area far below the diffraction limit. To reduce the self-heating effect in NFT, which could cause materials failure that leads to degradation of the overall hard drive performance, the NFT must deliver sufficient power to the recording medium with as small as possible incident laser power. In this talk, the optical design and characteristics of these plasmonic antennas and the effect of optical properties on field localization, absorption and coupling efficiency will be discussed. Heat dissipation at nanoscale, the induced temperature rise in NFT, and their dependence on materials’ properties will also be discussed. Other challenges involved in nanoscale materials, system engineering, and nano-manufacturing will also be addressed.