We propose that resonant inelastic x-ray scattering (RIXS) is an effective probe of the fractionalized excitations in three-dimensional (3D) Kitaev spin liquids. While the non-spin-conserving RIXS responses are dominated by the gauge-flux excitations and reproduce the inelastic-neutron-scattering response, the spin-conserving (SC) RIXS response picks up the Majorana-fermion excitations and detects whether they are gapless at Weyl points, nodal lines, or Fermi surfaces. As a signature of symmetry fractionalization, the SC RIXS response is suppressed around the Γ point. On a technical level, we calculate the exact SC RIXS responses of the Kitaev models on the hyperhoneycomb, stripyhoneycomb, hyperhexagon, and hyperoctagon lattices, arguing that our main results also apply to generic 3D Kitaev spin liquids beyond these exactly solvable models.
Bibliographical noteFunding Information:
We thank J. van den Brink, F. J. Burnell, J. T. Chalker, and J. Knolle for collaboration on closely related topics. G. B. H. is supported by the Gordon and Betty Moore Foundation’s EPiQS Initiative through Grant No. GBMF4304. N. B. P. is supported by the NSF Grant No. DMR-1511768 and is also grateful to the Perimeter Institute for their hospitality during the course of this work. Research at the Perimeter Institute is supported by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Economic Development and Innovation.
© 2017 American Physical Society.