1. Department
of Mechanical and Aerospace Engineering, University of California at San Diego, La Jolla, California 92093, United States
2. Department
of Electrical and Computer Engineering, University of California at San Diego, La Jolla, California 92093, United States
3. Center
for Magnetic Recording Research, University of California at San Diego, La
Jolla, California 92093, United States
4. Materials
Science and Engineering Program, University of California at San Diego, La
Jolla, California 92093, United States