Bulk spectroscopic measurement of the topological charge of Weyl nodes with resonant x-rays

Abstract

We formulate a bulk spectroscopic method for direct measurement of the topological invariant of nondegenerate band crossings in Weyl semimetals. We demonstrate how polarization-resolved resonant x-ray scattering captures the winding of the Berry flux around Weyl nodes. The spectra obtained by the proposed strategy feature an integer number of zero-crossings that is directly related to the topological charge of the measured nodes. We benchmark the proposed protocol on TaAs, using realistic low-energy models derived from density-functional theory to accurately represent the states close to the Fermi level, including sizable deviations from the idealized linear dispersion. We conclude that the proposed measurement, which is within the reach of current experimental setups, yields direct signatures of nontrivial band topology in spectroscopy of three-dimensional bulk matter.

v2: published version

References in corpus (11)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Topological response in Weyl semimetals and the chiral anomaly
• Quasiparticle interference of the Fermi arcs and surface-bulk connectivity of a Weyl semimetal
• Excitonic quasiparticles in a spin-orbit Mott insulator
• Observation of the Adler-Bell-Jackiw chiral anomaly in a Weyl semimetal
• Electronic Evidence for Type II Weyl Semimetal State in MoTe2
• The simultaneous measurement of energy and linear polarization of the scattered radiation in resonant inelastic soft x-ray scattering
• Discovery of Weyl semimetal state violating Lorentz invariance in MoTe2
• Discovery of Lorentz-violating Weyl fermion semimetal state in LaAlGe materials
• Experimental signatures of phase interference and sub-femtosecond time dynamics on the incident energy axis of resonant inelastic X-ray scattering

Cited by in corpus (12)

• Quantized circular photogalvanic effect in Weyl semimetals
• Topological quantum properties of chiral crystals
• Chiral Optical Response of Multifold Fermions
• Momentum-space signatures of Berry flux monopoles in a Weyl semimetal
• Circular dichroism as a probe for topology in three-dimensional semimetals
• Signatures of two- and three-dimensional semimetals from circular dichroism
• Chern numbers of topological phonon band crossing determined with inelastic neutron scattering
• Monopole Charge Density Wave States in Weyl Semimetals
• Probing magnetic orbitals and Berry curvature with circular dichroism in resonant inelastic X-ray scattering
• Optical absorption in interacting and nonlinear Weyl semimetals
• Interplay of broken symmetry and delocalized excitations in the insulating state of 1$T$-TaS${}_2$
• Resonant inelastic X-ray scattering in the topological semimetal FeSi