Probing Spinon Nodal Structures in Three-Dimensional Kitaev Spin Liquids

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Spectroscopy

Background:

• Kitaev spin liquids exhibit exotic fractionalized excitations.
• Understanding these excitations is crucial for quantum computing and novel materials.
• Traditional probes like neutron scattering have limitations.

Purpose of the Study:

• To establish resonant inelastic x-ray scattering (RIXS) as a powerful tool for investigating three-dimensional (3D) Kitaev spin liquids.
• To differentiate between gauge-flux and Majorana-fermion excitations using RIXS.
• To identify signatures of symmetry fractionalization in RIXS spectra.

Main Methods:

• Theoretical calculation of RIXS responses for various 3D Kitaev models.
• Analysis of both non-spin-conserving and spin-conserving RIXS channels.
• Comparison of RIXS with inelastic neutron scattering.

Main Results:

• Non-spin-conserving RIXS probes gauge-flux excitations, consistent with neutron scattering.
• Spin-conserving RIXS uniquely identifies Majorana-fermion excitations.
• The suppression of spin-conserving RIXS around the Γ point indicates symmetry fractionalization.
• RIXS can determine if Majorana fermions are gapless at Weyl points, nodal lines, or Fermi surfaces.

Conclusions:

• RIXS is a highly effective spectroscopic method for characterizing 3D Kitaev spin liquids.
• Spin-conserving RIXS provides direct access to Majorana-fermion properties.
• The proposed RIXS approach is applicable to a broad range of 3D Kitaev spin liquids.