CORRELATED TOPOLOGICAL STATES AND QUANTUM ELECTRONIC NEMATICS AT THE INTERFACES BETWEEN A WEYL SEMIMETAL AND SPIN ICE

CORRELATED TOPOLOGICAL STATES AND QUANTUM ELECTRONIC NEMATICS ATTHE INTERFACES BETWEEN A WEYL SEMIMETAL AND SPIN ICEJ. Chakhalian, Rutgers, The State University of New JerseyThe recent advancements in synthesizing and discovering states and phenomena beyond the Landau symmetry-breaking paradigm in quantum materials have been remarkable. These new modalities challenge our understanding of the possible behavior of fermions and bosons in quantum crystals, yet they remain often concealed from current experimental probes in bulk. For example, a Weyl phase may be hidden in the magneto-transport in crystals with high cubic symmetry due to the perfect cancellation of monopole charges in the Brillouin zone. Also, a quantum nematic order parameter, being a rank-2 operator, to a linear order, does not couple to powerful spectroscopies based on photons or NMR. In addition, these correlated topological states are scarce in correlated electron systems. To address these challenges, the proposed research aims to (i) create new synthetic templates with rich many-body behavior derived from the remarkable class of magnetic Weyl semimetals of pyrochlore iridates and spin ices with magnetic monopole excitations and U(1) photons in rare-earth pyrochlore titanates and (ii) discover new quantum states and excitations stemming from dressed topological Fermi arcs by the massively degenerate spin states and fractionalized excitations of spin ice.The proposal aims to test two hypotheses: (1) that electronic quantum nematic states can arise from magnetic monopoles on rare-earth sites, coupled with the Weyl liquid in the oriented late-rare-earth iridium pyrochlore thin films, as well as in the heterointerface between a Weyl semimetal and spin ices of rare-earth titanates, (2) that by exciting the system with external stimuli including magnetic, photonic and electron fields, unusual bosonic modes can emerge in those material systems. To validate these hypotheses, state-of-the-art photon and electron probes will be used to experiment on the oriented films of heavy rare-earth pyrochlore iridates and their heterojunctions with the quantum and classical spin ices. The proposed discovery and exploration will contribute to the nascent field of synthetic correlated topological materials towards the practical manipulation of a ground state wave-function and control of emergent excitations. This step can be a significant milestone for quantum technologies and ultra low-power spintronics applications pertinent to the DOE-BES mission.