Speaker
Description
Pyrochlore oxides incorporating magnetic Ce$^{3+}$ have been the subject of intense experimental and theoretical efforts over the past few years. Their rich physics is related to their dipole-octupole magnetic degrees of freedom and possibility to stabilise a quantum spin ice (QSI) ground state -- the prototype three-dimensional quantum spin liquid. While all studied materials show continua of excitations attributed to the fractionalized spinon excitations of QSI, the nature of the underlying correlations has been subject to debates. Here we show using neutron scattering that Ce$_2$Hf$_2$O$_7$ develops hybrid dipolar-octupolar correlations. The large contrast between dipolar and octupolar form factors allows to determine the weak dipolar-octupolar exchange of the Hamiltonian.
