HMC Physics Colloquium

Tuesdays at 16:30 in Shanahan Center for Teaching and Learning, Room B460

Eric Fullerton (’84)

San Jose Research Center of Hitachi Global Storage Technologies

Bits of the Future: Magnetic Recording Beyond the Superparamagnetic Limit

Nov. 2, 2004

Storage densities of magnetic recording systems are currently doubling every year in both laboratory demonstrations and hard disk drive products. Increasing the storage density has mainly been achieved by scaling the head and media parameters to smaller dimensions. However, as many of the critical dimensions approach the nanometer scale, a variety of physical phenomena are predicted to limit the capacity of magnetic recording. One example is thermal instabilities in the recording media, often referred to as the "superparamagnetic limit." I will review current research on novel magnetic nano-structures that show promise in extending densities beyond these predicted limits. Examples will include antiferromagnetically-coupled recording media (currently used in all Hitachi products), perpendicular recording, thermally-assisted recording, patterned media and self-organized magnetic nano-particles.