RKKY

1. 2 3 Griffiths droplets 1 4 RKKY RKKY Interactions and Dissipation in Metallic Griffiths PhasesVladimir Dobrosavljevic, Florida State University, DMR-0234215 • Disorder and rare events completely change the behavior of magnetic systems close to a quantum critical point, leading to quantum Griffiths phases. • In metallic magnetsadditional long-ranged RKKY interactions couple the rare regions causing non-Ohmicdissipation. • In electronic Griffiths phases: (disordered heavy fermions far from magnetic ordering) this leads to disorder-induced fractionalization and spin liquid behavior (D. Tanaskovic, V. Dobrosavljevic, and E. Miranda, Phys. Rev. Lett. 2005, in press). • In magnetic Griffiths phases:RKKY interactions lead to dissipative freezing of magnetic droplets and the formation of cluster-glassphases (V. Dobrosavljevic and E. Miranda, Phys. Rev. Lett. 94, 187203 (2005)). • Both mechanism can lead to disorder-driven non-Fermi liquid behavior. Recent review: E. Miranda and V. Dobrosavljevic, Reports on Progress in Physics 68, 1-72 (2005) . RKKY interactions mediating non-Ohmic dissipation in magnetic Griffiths phases (top). Phase diagram of the induced cluster-glass phase (bottom).

2. RKKY Interactions and Dissipation in Metallic Griffiths PhasesVladimir Dobrosavljevic, Florida State University, DMR-0234215 • Outreach activities: • The PI presented a “Saturday Morning Physics” lecture “Physics on the Web” to High School students. • The PI participated in the Florida State University Physics Department Open House, with a display: “Physics of Paper Airplanes for Kids”. • The PI participated in the NHMFL Annual Open House activities with a display “Physics of Behind Magnetism”). • Educational: • One undergraduate student, two graduate students and a postdoc contributed to these projects. These students received training in many-body theory, including computer modeling and analytical calculations. Synergistic Activities: the PI, together with E. Dagotto, S. Sachdev, and J. Zaanen organized an international workshop at the Lorentz Center (Leiden, The Netherlands) that drew roughly 60 international participants.