Matthias Vojta

Motivated by the magnetism of pyrochlore oxides, we consider the effect of quantum fluctuations in the most general symmetry-allowed nearest-neighbor Kramers exchange Hamiltonian on the pyrochlore lattice. At the classical level, this Hamiltonian exhibits a rich landscape of classical spin liquids and a variety of nonconventional magnetic phases.

The destruction of the Kondo effect in a local-moment metal can lead to a topological non-Fermi-liquid phase, dubbed fractionalized Fermi liquid, with spinon-type excitations and an emergent gauge field. We demonstrate that, if the latter displays an internal π-flux structure, a chiral heavy-fermion metal emerges near the Kondo-breakdown transition.

One of the forefront fields of modern superconductivity research is that on hydrides at high pressures. Over the past few years, this research has attracted considerable publicity, of which a substantial fraction has been negative. Scientific fraud has been committed and exposed, and arguments continue about specific aspects of data presented in some other papers.