TY  - JOUR
AU  - Figgemeier, T.
AU  - Uenzelmann, Maximilian
AU  - Eck, P.
AU  - Schusser, Jakub
AU  - Crippa, Gabriele
AU  - Neu, J. N.
AU  - Geldiyev, B.
AU  - Kagerer, Philipp
AU  - Buck, J.
AU  - Kalläne, M.
AU  - Hoesch, M.
AU  - Rossnagel, K.
AU  - Siegrist, T.
AU  - Lim, L.-K.
AU  - Moessner, R.
AU  - Sangiovanni, G.
AU  - Di Sante, D.
AU  - Reinert, Friedrich
AU  - Bentmann, Hendrik
TI  - Imaging Orbital Vortex Lines in Three-Dimensional Momentum Space
JO  - Physical review / X
VL  - 15
IS  - 1
SN  - 2160-3308
CY  - College Park, Md.
PB  - APS
M1  - PUBDB-2025-00724
M1  - arXiv:2402.10031
SP  - 011032
PY  - 2025
AB  - 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. We determine the core of the orbital angular momentum vortex to host an almost movable, twofold, spin-degenerate Weyl nodal line, a topological feature predicted to occur in certain nonsymmorphic crystals. These results establish bimodal dichroism in SX-ARPES as a robust approach to trace 3D orbital textures. Our findings constitute the first imaging of nontrivial quantum-phase winding at line nodes and may pave the way to new orbitronic phenomena in quantum materials.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001444675500001
DO  - DOI:10.1103/PhysRevX.15.011032
UR  - https://bib-pubdb1.desy.de/record/623655
ER  -