Title: Spin Orbit Coupled Quantum Magnetism
Speaker:Kate Ross, Colorado State University
Abstract: “Quantum magnetism” refers to magnetic phases with physical properties that are determined by strong quantum fluctuations . These include phases in which spins are long range entangled, such the large number of theoretically predicted “Quantum Spin Liquid” (QSL) phases, from which exotic fractionalized quasi-particle excitations are expected to arise. The QSL phases have previously been sought in “spin only” magnetic materials that host isotropic interactions, and a few candidates have emerged. However, recently a new wave of quantum phases, including new and very promising QSL candidates, are being discovered in materials where the spin and orbital angular momenta of the unpaired electrons are intimately linked into a composite, highly anisotropic wavefunction, leading to anisotropic pairwise interactions. I will discuss the strongly spin orbit coupled pyrochlore materials and show how inelastic neutron scattering can be used to quantitatively determine their anisotropic interactions, providing a theoretical starting point for understanding its unusual dynamical properties. In one pyrochlore family, Yb2B2O7 (B = Ti, Ge, Sn), the unusual spin excitations may be the signature of fractionalized quasi-particles of a nearby Quantum Spin Liquid.
Host: Goswami
Speaker Schedule
Keywords: Physics, Astronomy, colloquium