CANADIAN: Momentum dependence of crystal field levels in CeRhIn5

In Kondo systems, localized f-electron states hybridize with itinerant electrons, leading to an emergent many-body state. Modern electronic structure calculations indicate that excited crystal electric field (CEF) and spin-orbit levels of the f-electron manifold need to be considered in strongly correlated metals such as the Kondo materials. Recent RIXS and ARPES experiments both indicate that these excited states acquire momentum dependence due to Kondo hybridization. Through the dynamical magnetic susceptibility, neutron scattering should access another aspect of this interesting momentum dependence. Yet, we are not aware of any single crystal neutron scattering studies of heavy fermion materials that could shed light Q-dependences of CEF levels. To investigate this subject, we propose to measure the single crystal inelastic spectrum of the heavy fermion material CeRhIn5 with the MAPS spectrometer with an incident energy of 50 meV. We request a total of 8 days to measure Q-dependences of the CEF levels in the antiferromagnetic, coherent paramagnetic and incoherent paramagnetic phases. The experiment will be performed on a well-characterized sample that has already been used to study the low-energy spin wave excitations.