Event



Condensed Matter Seminar: TOPOLOGICAL STATES in MAGNETIC PYROCHLORE IRIDATES

Jak Chakhalian (Rutgers University)
- | David Rittenhouse Laboratory, A4

Magnetic Weyl semimetals have recently garnered significant attention due to their unique electronic properties. Unlike conventional metals and semimetals, Weyl semimetals are characterized by a specific type of band crossing known as a Weyl node carrying a topological charge. This leads to several interesting phenomena, such as the chiral anomaly and Fermi arcs on the material's surface. In addition, adding magnetism to these materials results in unusual magneto-transport response, including the possibility of negative magnetoresistance and the appearance of topological Hall currents.

All together these compounds contribute to the recent progress in synthesizing and discovering states and phenomena beyond the Landau symmetry-breaking. However, though those new findings confront our views of fermions and bosons' possible behavior in solids, in bulk they may remain concealed from the experimental probes. For instance, in crystals of cubic symmetry, Weyl fermions are hidden in the magneto-transport due to the perfect cancellation of monopole charges. To exacerbate, experimentally by  now topological phases are well-known for non-correlated compounds, but they are scarcely found in correlated electron systems. In this talk, I will discuss the fresh ways to address two challenges by (1) creating new synthetic templates with rich many-body behavior derived from the class of rare-earth pyrochlore iridates and (2) discovering interesting states and phenomena entwined with spin correlations and non-trivial band topology arising from breaking time-reversal or inversion symmetry including Weyl semimetal, and potentially gaped Dirac and surface axionic states upon application of an external magnetic field or uniaxial strain. Specifically, I will focus on the feasibility of experimental validation of those states and their magnetic excitations within the oriented films of synthetic frustrated Kagome-triangular materials with entangled fermions and large spin-orbit interaction.