1. Novel contribution to the Anomalous Hall Effect in HelimagnetsJohn F. DiTusa, Louisiana State University & Agricultural and Mechanical College, DMR 1206763 The anomalous Hall effect (AHE) is the dominant contribution to the transverse conductivity in magnets which stems from a quantum mechanical coupling of the electronic spin and orbital angular momenta. Here, we find that the accepted model (solid line in a-c) systematically fails to describe the AHE in a series of isostructural silicide and germanide transition metal compounds. We have thus identified a new contribution to the AHE that extends beyond the Curie point, is largest near the saturation field, and includes regions identified as hosting the newly discovered topological Skyrmion lattice phase. We conclude that the magnetic state of these materials is likely much more complex and interesting than previously thought. Crystal structure of B20 transition metal compounds. The absence of inversion symmetry is thought responsible for the interesting magnetic properties of these materials.

2. Graduate and Undergraduate Education, Research and OutreachJohn F. DiTusa, Louisiana State University & Agricultural and Mechanical College, DMR 1206763 REU student Chris Kiernen, BRCC student and Marine Corp veteran, synthesized compounds lacking inversion symmetry in their crystal structures. He discovered previously unreported magnetic states where we believe spin-orbit effects may lead to topologically interesting magnetic phenomena. Over 20 undergraduate students have participated in the NSF supported research, many have gone on to graduate programs and careers in science.This grant supported the work of Teach for America participants Joshua Miller, and Patrick Turk as we sought to engage minority K-12 students through their work and visits of their students to our labs Education: The work ofPhysics graduate Students Drew Rebar and Yan Wu, and undergraduate students Noah Davis, Josua Mendez, Dominique Gautreau, and Chris Kieren is supported by this research grant. Previous post docs and graduate students, whose PhD and masters thesis research were supported by this program, are now employed in research, education, and industry on three continents.