Research: Order out of a Coulomb Phase and Higgs Transition in Nd2Zr2O7

The pyrochlore material Nd₂Zr₂O₇ shows novel quantum moment fragmentation. Antiferromagnetic an “all-in-all-out” long-range magnetic order coexists with a dynamical pinch point pattern that appears in the excitations as a gapped flat mode.  The parametrized spin Hamiltonian has a dominant frustrated ferromagnetic term which gives rise to the pinch point pattern and reveals a proximity to a U(1) spin liquid. The magnetic excitations of Nd₂Zr₂O₇ above the ordering temperature were explored using high-energy-resolution inelastic neutron scattering. The results relate the magnetic ordering of Nd₂Zr₂O₇ with the Higgs mechanism and provide explanations for several previously reported experimental features.

J. Xu, O. Benton, A.T.M.N. Islam, T. Guidi, G. Ehlers, B. Lake,
Order out of a Coulomb Phase and Higgs Transition: Frustrated Transverse Interactions of Nd₂Zr₂O₇,
Phys. Rev. Lett. 124, 097203 (2020) (arXiv)