Electron Orbital Angular Momentum and the Rise of Orbitronics

By Abdul Ahad NazakatReviewed by Louis CastelAug 6 2025

Electron spin has driven quantum technology development for decades, but researchers are now focusing another property: orbital angular momentum (OAM). OAM refers to the wave-like spatial distribution of an electron’s motion, offering quantum degrees of freedom that go beyond the binary nature of spin. This article explores recent progress in manipulating electron OAM, its potential applications in quantum computing and spintronics, and how this growing field is beginning to take shape commercially.

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Orbital vs. Spin: Expanding the Quantum Toolkit

Every electron possesses two forms of angular momentum, Spin Angular Momentum (SAM) and Orbital Angular Momentum (OAM), with each having distinct characteristics. Spin Angular Momentum (SAM) is an intrinsic property similar to a top spinning on its axis, typically existing in binary "up" and "down" states. Orbital Angular Momentum (OAM), on the other hand, relates to the spatial distribution of the electron's wave function, characterized by a phase gradient that creates a twisting motion through space.^1,2

This distinction creates new possibilities for quantum information processing. The binary nature of spin forms the foundation of qubits, but OAM can take on multiple discrete values. This enables the creation of qudits: quantum units that exist in three, four, or more levels. These multi-level systems can encode more information per particle, thereby boosting efficiency and security in quantum cryptography.³

The spatial characteristics of OAM states also provide different noise resilience properties compared to spin states. Combining OAM with spin-orbit coupling produces phenomena like the spin-orbital-Hall effect, where charge currents generate both spin and orbital angular momentum currents in materials.¹

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Recent Advances in OAM Control

Practical control of OAM has progressed mainly through two key approaches: shaping electron beams externally and leveraging the intrinsic properties of materials.

External control methods have achieved notable precision. Researchers have created electron vortex beams carrying OAM values up to L = 1000ℏ using nano-fabricated holograms and phase plates, enabling detailed probing of material electronic and magnetic properties.⁴ These high-OAM beams serve as sensitive tools for studying quantum materials and their responses to twisted electron states.

Intrinsic OAM generation represents a parallel track in this development, focusing on materials that naturally induce orbital angular momentum without the need for external beam shaping. Studies of chiral topological semimetals, including platinum gallium (PtGa) and palladium gallium (PdGa), have demonstrated controllable "OAM monopoles". These are essentially localized sources of orbital angular momentum that are embedded directly within the material's electronic structure. Using circular dichroism in angle-resolved photoelectron spectroscopy (CD-ARPES), researchers showed that these monopoles' polarity can be controlled by altering the crystal's structural handedness.⁵ This approach eliminates the need for external magnetic fields, simplifying device architectures.

Applications in Quantum Computing and Spintronics

OAM integration into quantum systems addresses several technical challenges. In silicon qubits, spin-orbit coupling effects can extend coherence times to 10 milliseconds, compared with shorter durations in conventional spin-only systems.⁶ In superconducting circuits, OAM states could provide additional control mechanisms for qubit manipulation and error correction, though experimental demonstrations remain limited. This improvement arises from OAM's ability to create topologically protected states that resist certain types of environmental decoherence.⁷

Multi-level qudits enabled by OAM offer computational advantages through increased information density and natural error correction mechanisms. Systems with more quantum levels can implement certain algorithms more efficiently and provide redundancy against quantum errors.³

The spin-OAM interaction also enables new types of quantum logic gates. Demonstrations of OAM-assisted spin-directional coupling in photonic circuits show potential for on-chip quantum operations that leverage both angular momentum types simultaneously.⁸

Commercial and Industrial Development

Technology companies are beginning to explore OAM applications. IBM and Microsoft Quantum are investigating how OAM properties might enhance quantum system performance, while research institutions like QuTech are studying OAM integration into quantum key distribution networks. Companies such as Riverlane are examining how quantum algorithms and error correction protocols might adapt to hardware that utilizes OAM states.

Hardware development is progressing alongside theoretical work. Photonic integrated circuits designed specifically for OAM mode generation enable parallel quantum communication channels (Zahidy et al., 2021).⁹ Vertical-cavity surface-emitting lasers (VCSELs) provide efficient OAM beam generation for optical applications (Li et al., 2015).¹⁰ Patent activity in OAM multiplexing technologies indicates growing commercial interest, with significant patent filings in recent years, though most applications remain in research phases (Liu et al., 2020).¹¹

Technical Challenges and Future Directions

Several obstacles limit current OAM implementations. Maintaining coherence of OAM states against environmental noise remains difficult, particularly in solid-state systems.⁷ Accurately measuring and distinguishing different OAM states requires precision beyond current detection capabilities, though machine learning approaches show promise for improving state recognition from noisy data.¹²

Research efforts are addressing these limitations through multiple approaches. The HOBBIT system demonstrates rapid, tunable OAM generation for experimental studies (Li et al., 2019).¹³ Theoretical work continues to explore fundamental limits of OAM-based quantum communication and computation.

Long-term applications may include OAM-enhanced quantum sensors capable of detecting subtle electromagnetic fields, with applications in medical imaging and navigation. However, significant technical development remains necessary before these applications become practical. As researcher Yen noted in their recent Nature Physics study, "The potential of OAM in enhancing quantum memory and sensor capabilities requires overcoming substantial technical hurdles in coherence and readout precision".⁵

What’s Next for Orbitronics?

Research into electron orbital angular momentum is moving beyond fundamental studies and edging closer to practical applications. Recent progress in both externally generated OAM and material-based intrinsic control is opening up new ways to explore quantum systems with expanded degrees of freedom. While challenges remain, such as maintaining coherence, improving readout precision, and scaling devices, ongoing work in materials science, device engineering, and quantum algorithm development is steadily tackling these hurdles.

The field's development will likely determine whether OAM-based systems complement or enhance current quantum technologies, rather than replacing them entirely. Success will depend on overcoming technical hurdles and identifying applications where OAM's unique properties provide clear advantages over existing approaches.

References and Further Reading’

1. Liu, L., Sun, X., Tian, Y., Zhang, X., Lu, M., & Chen, Y. (2024). Cyclic Evolution of Synergized Spin and Orbital Angular Momenta. Advanced Science. https://doi.org/10.1002/advs.202409377
2. McMorran, B. J., Agrawal, A., Agrawal, A., Ercius, P., Grillo, V., Herzing, A. A., Harvey, T. R., Linck, M., & Pierce, J. S. (2017). Origins and demonstrations of electrons with orbital angular momentum. Philosophical Transactions of the Royal Society A, 375(2087), 20150434. https://doi.org/10.1098/RSTA.2015.0434
3. Nagali, E., Marrucci, L., Santamato, E., & Sciarrino, F. (2011). Engineering of photonic orbital angular momentum quantum states for quantum information processing. European Quantum Electronics Conference, 1. https://doi.org/10.1109/CLEOE.2011.5943445
4. Mafakheri, E., Tavabi, A. H., Lu, P.-H., Balboni, R., Venturi, F., Menozzi, C., Gazzadi, G. C., Frabboni, S., Sit, A., Dunin-Borkowski, R. E., Karimi, E., & Grillo, V. (2017). Realization of electron vortices with large orbital angular momentum using miniature holograms fabricated by electron beam lithography. Applied Physics Letters, 110(9), 093113. https://doi.org/10.1063/1.4977879
5. Yen, Y., Krieger, J. A., Yao, M., Robredo, I., Manna, K., Yang, Q., McFarlane, E. C., Shekhar, C., Borrmann, H., Stolz, S., Widmer, R., Gröning, O., Strocov, V. N., Parkin, S., Felser, C., Vergniory, M. G., Schüler, M., & Schröter, N. B. M. (2024). Controllable orbital angular momentum monopoles in chiral topological semimetals. Nature Physics. https://doi.org/10.1038/s41567-024-02655-1
6. Kobayashi, T., Kobayashi, T., Kobayashi, T., Salfi, J., Chua, C., van der Heijden, J., House, M., Culcer, D., Hutchison, W. D., Johnson, B. C., McCallum, J. C., Riemann, H., Abrosimov, N. V., Becker, P. B., Pohl, H.-J., Simmons, M. Y., & Rogge, S. (2021). Engineering long spin coherence times of spin-orbit qubits in silicon. Nature Materials, 20(1), 38–42. https://doi.org/10.1038/S41563-020-0743-3
7. Jo, D., Go, D., Choi, G.-M., & Lee, H. (2024). Spintronics meets orbitronics: Emergence of orbital angular momentum in solids. Npj Spintronics, 2(1). https://doi.org/10.1038/s44306-024-00023-6
8. Shao, Z., Zhu, J., Zhang, Y., Zhu, G., Yang, Z., Chen, Y., & Yu, S. (2017). Orbital angular momentum assisted spin-directional coupling. Conference on Lasers and Electro-Optics, 1–4. https://doi.org/10.1109/CLEOPR.2017.8118741
9. Zahidy, M., Liu, Y., Cozzolino, D., Ding, Y., Morioka, T., Oxenløwe, L. K., & Bacco, D. (2021). Photonic integrated chip enabling orbital angular momentum multiplexing for quantum communication. Nanophotonics. https://doi.org/10.1515/NANOPH-2021-0500
10. Li, H., Phillips, D. B., Wang, X., Ho, Y.-L. D., Chen, L., Zhou, X.-Q., Zhu, J., Yu, S., & Cai, X. (2015). Orbital angular momentum vertical-cavity surface-emitting lasers. 2(6), 547–552. https://doi.org/10.1364/OPTICA.2.000547
11. Liu, S., Lou, Y., Jing, J., Jing, J., & Jing, J. (2020). Orbital angular momentum multiplexed deterministic all-optical quantum teleportation. Nature Communications, 11(1), 3875. https://doi.org/10.1038/S41467-020-17616-4
12. Zhou, J., Tang, J., Yin, Y., Xia, Y., & Yin, J. (2024). Fundamental probing limit on the high-order orbital angular momentum of light. Optics Express. https://doi.org/10.1364/oe.516620
13. Li, W., Morgan, K., Li, Y., Miller, J. K., White, G., Watkins, R. J., & Johnson, E. G. (2019). Rapidly tunable orbital angular momentum (OAM) system for higher order Bessel beams integrated in time (HOBBIT). Optics Express, 27(4), 3920–3934. https://doi.org/10.1364/OE.27.003920​​​​​​​​​​​​

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