[1] NIST, Joint Quantum Inst, College Pk, MD 20742 USA
[2] Univ Maryland, College Pk, MD 20742 USA
[3] Univ Maryland, Dept Phys, College Pk, MD 20742 USA
[4] Univ Maryland, Dept Elect Engn, College Pk, MD 20742 USA
[5] Univ Maryland, Dept Comp Engn, College Pk, MD 20742 USA
[6] Univ Maryland, Inst Res Elect & Appl Phys, College Pk, MD 20742 USA
[7] Argonne Natl Lab, Mat Sci Div, 9700 S Cass Ave, Argonne, IL 60439 USA