Observation of spin-free interatomic orbital angular momentum in a chiral crystal

@misc{oh2026observation,
  title = {{Observation of spin-free interatomic orbital angular momentum in a chiral crystal}},
  author = {Dongjin Oh and Sungsoo Hahn and Chiara Pacella and Junseo Yoo and Angel Rubio and Domenico Di Sante and Changyoung Kim},
  howpublished = {arXiv},
  year = {2026},
  month = aug,
  doi = {10.48550/arxiv.2605.21124},
  eprint = {2605.21124},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2605.21124},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Observation of spin-free interatomic orbital angular momentum in a chiral crystal
AU  - Dongjin Oh
AU  - Sungsoo Hahn
AU  - Chiara Pacella
AU  - Junseo Yoo
AU  - Angel Rubio
AU  - Domenico Di Sante
AU  - Changyoung Kim
PY  - 2026
DA  - 2026/08/28
PB  - arXiv
DO  - 10.48550/arxiv.2605.21124
UR  - https://arxiv.org/abs/2605.21124
AB  - The inherent spin-orbit interaction of electrons inevitably couples spin to the orbital angular momentum (OAM), posing a fundamental challenge to spin-free orbital transport. Here, we propose a novel strategy to achieve spin-decoupled OAM states in crystalline solids. Using angle-resolved photoemission spectroscopy (ARPES), we resolve well-isolated s-orbital bands in a chiral Te crystal, clearly separated from the p-orbital manifold. Combined circular dichroism ARPES and first-principles calculations reveal that these bands host OAM arising exclusively from interatomic hopping, with no intra-atomic contribution. Spin-resolved ARPES further confirms the absence of spin angular momentum (SAM), providing decisive evidence of spin-free OAM states. These findings establish the existence of OAM without spin polarization in crystalline solids and highlight the essential role of inter-atomic OAM. This work provides a general framework for designing spinless OAM states, opening an opportunity toward pure orbital currents for orbitronics.
ER  -