20 likes | 112 Vues
New Magnetic States from Geometrical Frustration Meigan C. Aronson, Stony Brook University, DMR 0405961.
E N D
New Magnetic States from Geometrical FrustrationMeigan C. Aronson, Stony Brook University,DMR 0405961 Magnetic order occurs when the moments of atoms interact and the temperature is low enough to preserve this ordering. Can we defeat conventional magnetic order and create new magnetic states simply by changing the geometry of the lattice on which the moments form? We have discovered a new material Yb2Pt2Pb, which forms on a geometrically frustrated `Shastry-Sutherland Lattice’. Magnetic order is very weak in Yb2Pt2Pb, and the Yb moments only remain ordered for short times and over short distances. Applying a field completely destroys magnetic order, but drives a series of new magnetic and electronic states, involving the Bose-Einstein condensation of pairs of coupled Yb moments, which can be magnetic or not. Different types of magnetic order are found when magnetic fields are applied to Yb2Pt2Pb, where the magnetic Yb atoms lie on the geometrically frustrated `Shastry-Sutherland’ lattice, indicated. No magnetic order is found above 2.4 Tesla.
New Magnetic States from Geometrical FrustrationMeigan C. Aronson, Stony Brook University,DMR 0405961 Our broader impact focuses on the participation of undergraduate and graduate students in our research. Undergraduate students carry out most of the sample synthesis activities in our lab, and in the last year we had three students involved - Victor Leyva, Jude Safo, and Carlos Marques - all from traditionally underrepresented groups. All discovered new compounds, and will be coauthors of papers describing these results. Safo and Marques are applying to physics graduate programs. Safo has received an NSF Graduate Fellowship. Our group (summer 2010) . Back row (from left): Keeseong Park (PD), Jude Safo (UG), Carlos Marques (UG), Liusuo Wu (G) Front row (from left) Yuri Janssen (PD), Meigan Aronson (PI), and Moosung Kim (PD). Not shown: Victor Leyva (UG) Safo, Marques, Leyva, Wu, and Kim received full or partial support from this project.