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Synthetic spin–orbit interaction for Majorana devices

Abstract

The interplay of superconductivity with non-trivial spin textures is promising for the engineering of non-Abelian Majorana quasiparticles. Spin–orbit coupling is crucial for the topological protection of Majorana modes as it forbids other trivial excitations at low energy but is typically intrinsic to the material1,2,3,4,5,6,7. Here, we show that coupling to a magnetic texture can induce both a strong spin–orbit coupling of 1.1 meV and a Zeeman effect in a carbon nanotube. Both of these features are revealed through oscillations of superconductivity-induced subgap states under a change in the magnetic texture. Furthermore, we find a robust zero-energy state—the hallmark of devices hosting localized Majorana modes—at zero magnetic field. Our findings are generalizable to any low-dimensional conductor, and future work could include microwave spectroscopy and braiding operations, which are at the heart of modern schemes for topological quantum computation.

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Fig. 1: Hybrid superconductor–nanotube–magnetic texture set-up.
Fig. 2: Oscillations of the subgap states and synthetic spin–orbit interaction.
Fig. 3: Control experiment and phenomenology of subgap states under a magnetic field.
Fig. 4: Zero-bias peak.

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Data availability

The authors declare that the main data supporting the findings of this study are available within the article (main text, methods and Supplementary information). Extra data are available from the corresponding author on reasonable request.

Code availability

The codes used in this paper are available at https://github.com/Exopy.

References

  1. Oreg, Y., Refael, G. & Von Oppen, F. Helical liquids and Majorana bound states in quantum wires. Phys. Rev. Lett. 105, 177002 (2010).

    Article  Google Scholar 

  2. Lutchyn, R. M., Sau, J. D. & Das Sarma, S. Majorana fermions and a topological phase transition in semiconductor-superconductor heterostructures. Phys. Rev. Lett. 105, 077001 (2010).

    Article  Google Scholar 

  3. Zhang, H. et al. Quantized Majorana conductance. Nature 556, 74–79 (2018).

    Article  CAS  Google Scholar 

  4. Das, A. et al. Zero-bias peaks and splitting in an Al-InAs nanowire topological superconductor as a signature of Majorana fermions. Nat. Phys. 8, 887–895 (2012).

    Article  CAS  Google Scholar 

  5. Albrecht, S. M. et al. Exponential protection of zero modes in Majorana islands. Nature 531, 206–209 (2016).

    Article  CAS  Google Scholar 

  6. Nadj-Perge, S. et al. Observation of Majorana fermions in ferromagnetic atomic chains on a superconductor. Science 346, 602–607 (2014).

    Article  CAS  Google Scholar 

  7. Deng, M. T. et al. Majorana bound state in a coupled quantum-dot hybrid-nanowire system. Science 354, 1557–1562 (2016).

    Article  CAS  Google Scholar 

  8. Braunecker, B., Japaridze, G. I., Klinovaja, J. & Loss, D. Spin-selective peierls transition in interacting one-dimensional conductors with spin-orbit interaction. Phys. Rev. B 82, 045127 (2010).

    Article  Google Scholar 

  9. Klinovaja, J., Stano, P. & Loss, D. Transition from fractional to Majorana fermions in Rashba nanowires. Phys. Rev. Lett. 109, 236801 (2012).

    Article  Google Scholar 

  10. Klinovaja, J., Stano, P., Yazdani, A. & Loss, D. Topological superconductivity and Majorana fermions in RKKY systems. Phys. Rev. Lett. 111, 186805 (2013).

    Article  Google Scholar 

  11. Kjaergaard, M., Wölms, K. & Flensberg, K. Majorana fermions in superconducting nanowires without spin-orbit coupling. Phys. Rev. B 85, 020503(R) (2012).

    Article  Google Scholar 

  12. Egger, R. & Flensberg, K. Emerging dirac and Majorana fermions for carbon nanotubes with proximity-induced pairing and spiral magnetic field. Phys. Rev. B 85, 235462 (2012).

    Article  Google Scholar 

  13. Klinovaja, J. & Loss, D. Giant spin-orbit interaction due to rotating magnetic fields in graphene nanoribbons. Phys. Rev. X 3, 011008 (2013).

    Google Scholar 

  14. Nadj-Perge, S., Drozdov, I. K., Bernevig, B. A. & Yazdani, A. Proposal for realizing Majorana fermions in chains of magnetic atoms on a superconductor. Phys. Rev. B 88, 020407 (2013).

    Article  Google Scholar 

  15. Pientka, F., Glazman, L. I. & Von Oppen, F. Topological superconducting phase in helical Shiba chains. Phys. Rev. B 88, 155420 (2013).

    Article  Google Scholar 

  16. Choy, T.-P., Edge, J. M., Akhmerov, A. R. & Beenakker, C. W. J. Majorana fermions emerging from magnetic nanoparticles on a superconductor without spin-orbit coupling. Phys. Rev. B 84, 195442 (2011).

    Article  Google Scholar 

  17. Su, Z. et al. Mirage Andreev spectra generated by mesoscopic leads in nanowire quantum dots. Phys. Rev. Lett. 121, 127705 (2018).

    Article  CAS  Google Scholar 

  18. Yokoyama, T., Eto, M. & Nazarov, Y. V. Josephson current through semiconductor nanowire with spin-orbit interaction in magnetic field. J. Phys. Soc. Jpn. 82, 054703 (2013).

    Article  Google Scholar 

  19. San-Jose, P., Cayao, J., Prada, E. & Aguado, R. Majorana bound states from exceptional points in non-topological superconductors. Sci. Rep 6, 21427 (2016).

    Article  CAS  Google Scholar 

  20. Keidel, F., Burset, P. & Trauzettel, B. Tunable hybridization of Majorana bound states at the quantum spin Hall edge. Phys. Rev. B 97, 075408 (2018).

    Article  CAS  Google Scholar 

  21. Peñaranda, F., Aguado, R., San-Jose, P. & Prada, E. Quantifying wave-function overlaps in inhomogeneous Majorana nanowires. Phys. Rev. B 98, 235406 (2018).

    Article  Google Scholar 

  22. Danon, J., Hansen, E. B. & Flensberg, K. Conductance spectroscopy on Majorana wires and the inverse proximity effect. Phys. Rev. B 96, 125420 (2017).

    Article  Google Scholar 

  23. Liu, J., Potter, A., Law, K. & Lee, P. Zero-bias peaks in the tunneling conductance of spin-orbit-coupled superconducting wires with and without Majorana end-states. Phys. Rev. Lett. 109, 267002 (2012).

    Article  Google Scholar 

  24. Rainis, D., Trifunovic, L., Klinovaja, J. & Loss, D. Towards a realistic transport modeling in a superconducting nanowire with Majorana fermions. Phys. Rev. B 87, 024515 (2013).

    Article  Google Scholar 

  25. Liu, C.-X., Sau, J. D., Stanescu, T. D. & Das Sarma, S. Andreev bound states versus Majorana bound states in quantum dot-nanowire-superconductor hybrid structures: trivial versus topological zero-bias conductance peaks. Phys. Rev. B 96, 075161 (2017).

    Article  Google Scholar 

  26. Cottet, A., Kontos, T. & Douçot, B. Squeezing light with Majorana fermions. Phys. Rev. B 88, 195415 (2013).

    Article  Google Scholar 

  27. Van Woerkom, D. J. et al. Microwave spectroscopy of spinful Andreev bound states in ballistic semiconductor Josephson junctions. Nature Phys. 13, 876–881 (2017).

    Article  Google Scholar 

  28. Väyrynen, J. I., Rastelli, G., Belzig, W. & Glazman, L. I. Microwave signatures of Majorana states in a topological Josephson junction. Phys. Rev. B 92, 134508 (2015).

    Article  Google Scholar 

  29. Dartiailh, M. C., Kontos, T., Douçot, B. & Cottet, A. Direct cavity detection of Majorana pairs. Phys. Rev. Lett. 118, 126803 (2017).

    Article  Google Scholar 

  30. Fatin, G. L., Matos-Abiague, A., Scharf, B. & Žutić, I. Wireless Majorana bound states: from magnetic tunability to braiding. Phys. Rev. Lett. 117, 077002 (2016).

    Article  Google Scholar 

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Acknowledgements

We are indebted to B. Leridon for the SQUID measurements and to K. Bouzehouane for MFM measurements. We acknowledge J. Palomo, M. Rosticher, A. Pierret and A. Denis for technical support. L.C.C. acknowledges the support from a Foundation CFM-J.P. Aguilar grant. The devices were made within the consortium Salle Blanche Paris Centre. This work is supported by ERC Starting Grant CIRQYS and grants from Région Ile de France and the ANR FunTheme.

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Contributions

M.M.D. set up the experiment, and L.C.C. made the devices and carried out the measurements with the help of T.K. L.C.C. and M.M.D. performed the analysis of the data with inputs from T.K. L.C.C. and M.R.D. carried out the fabrication, measurement and analysis of the control experiment. M.M.D., J.J.V. and L.E.B. contributed through early experiments and the development of the nanofabrication process. T.C. and F.M. contributed to the experimental aspects. M.C.D. developed the data acquisition software. S.R. and A.T. developed the magnetic texture process and carried out the magnetic characterization with M.M.D. and L.C.C. M.M.D., L.C.C., M.R.D., T.K. and A.C. carried out the theory for the ABS oscillations. M.M.D. studied the tight-binding model using a framework developed by M.C.D. with theoretical insight from A.C. T.K., M.M.D., L.C.C., M.R.D. and A.C. co-wrote the manuscript with inputs from all the authors.

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Correspondence to T. Kontos.

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Supplementary Notes 1–7, Figs. 1–16 and references.

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Desjardins, M.M., Contamin, L.C., Delbecq, M.R. et al. Synthetic spin–orbit interaction for Majorana devices. Nat. Mater. 18, 1060–1064 (2019). https://doi.org/10.1038/s41563-019-0457-6

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