M. D. Stiles¹, W. M. Saslow², M. J. Donahue³, and A. Zangwill⁴

• ¹Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8412, USA
• ²Department of Physics, Texas A&M University, College Station, Texas 77843-4242, USA
• ³Mathematical and Computational Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8910, USA
• ⁴School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA