[1] Department of Materials Science and Engineering, University of Wisconsin, Madison,WI,53706, United States
[2] Department of Physics, University of California, Berkeley,CA,94720, United States
[3] Department of Physics, Grand Valley State University, Allendale,MI,49401, United States
[4] Department of Physics, University of Michigan, Ann Arbor,MI,48109, United States
[5] Naval Research Laboratory, Washington,DC,20375, United States