[PAST EVENT] Yudistira Virgus : Physics Dissertation Defense

May 8, 2015
10am - 1pm
Small Hall, Room 122
300 Ukrop Way
Williamsburg, VA 23185Map this location
Abstract: Graphene, a single layer of hexagonally bonded carbon atoms, is often hailed as a wonder material due to its remarkable intrinsic properties. It is the thinnest, the strongest, and the most stretchable crystal ever measured. Of all semiconductors, it also exhibits the highest electron mobility and current density at room temperature. One potential application of graphene is for use in spintronic devices. However, external methods are required to induce magnetism on graphene, since pristine graphene is nonmagnetic. One proposal is to adsorb transition metal atoms to provide localized magnetic moments in graphene. Single Co atoms on graphene, in particular, have been extensively studied both theoretically and experimentally. Previous calculations, however, show significantly varying results on the bonding nature of Co/graphene system and none of the calculations is fully consistent with the experimental results. We investigate the stability and electronic properties of single Co atoms on graphene with near-exact auxiliary-field quantum Monte Carlo.
Our findings are consistent with and provide an explanation for experimental results with Co on free-standing graphene.

Bio: Yudistira Virgus was born on August 28, 1985 in Palembang, South Sumatra, Indonesia. In 2004, he represented Indonesia in the XXXV International Physics Olympiad in Pohang, Korea and won a gold medal. In the same year, he pursued his interest in science by studying physics at the Institut Teknologi Bandung, in Bandung, West Java, Indonesia. He graduated with Cum Laude honors in July 2008. He entered College of William & Mary in Williamsburg, Virginia in Fall 2009 to study in the physics graduate program. In the fall of 2010, he joined Dr. Henry Krakauer and Dr. Shiwei Zhang's computational condensed matter physics group.