Tomographic Imaging of Orbital Vortex Lines in Three-Dimensional Momentum Space
Abstract
We report the experimental discovery of orbital vortex lines in the three-dimensional (3D) band structure of a topological semimetal. Combining linear and circular dichroism in soft x-ray angle-resolved photoemission (SX-ARPES) with first-principles theory, we image the winding of atomic orbital angular momentum, thereby revealing - and determining the location of - lines of vorticity in full 3D momentum space. Our observation of momentum-space vortex lines with quantized winding number establishes an analogue to real-space quantum vortices, for instance, in type-II superconductors and certain non-collinear magnets. These results establish multimodal dichroism in SX-ARPES as an approach to trace 3D orbital textures. Our present findings particularly constitute the first imaging of non-trivial quantum-phase winding at line nodes and may pave the way to new orbitronic phenomena in quantum materials
Keywords
Cite
@article{arxiv.2402.10031,
title = {Tomographic Imaging of Orbital Vortex Lines in Three-Dimensional Momentum Space},
author = {T. Figgemeier and M. Ünzelmann and P. Eck and J. Schusser and L. Crippa and J. N. Neu and B. Geldiyev and P. Kagerer and J. Buck and M. Kalläne and M. Hoesch and K. Rossnagel and T. Siegrist and L. -K. Lim and R. Moessner and G. Sangiovanni and D. Di Sante and F. Reinert and H. Bentmann},
journal= {arXiv preprint arXiv:2402.10031},
year = {2024}
}