Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Ultrafast hole spin qubit with gate-tunable spin–orbit switch functionality

An Author Correction to this article was published on 05 July 2021

This article has been updated


Quantum computers promise to execute complex tasks exponentially faster than any possible classical computer, and thus spur breakthroughs in quantum chemistry, material science and machine learning. However, quantum computers require fast and selective control of large numbers of individual qubits while maintaining coherence. Qubits based on hole spins in one-dimensional germanium/silicon nanostructures are predicted to experience an exceptionally strong yet electrically tunable spin–orbit interaction, which allows us to optimize qubit performance by switching between distinct modes of ultrafast manipulation, long coherence and individual addressability. Here we used millivolt gate voltage changes to tune the Rabi frequency of a hole spin qubit in a germanium/silicon nanowire from 31 to 219 MHz, its driven coherence time between 7 and 59 ns, and its Landé g-factor from 0.83 to 1.27. We thus demonstrated spin–orbit switch functionality, with on/off ratios of roughly seven, which could be further increased through improved gate design. Finally, we used this control to optimize our qubit further and approach the strong driving regime, with spin-flipping times as short as ~1 ns.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Experimental set-up and EDSR.
Fig. 2: Coherent qubit control.
Fig. 3: Electrical tunability of qubit parameters.
Fig. 4: Ultrafast coherent control.

Data availability

The data supporting the plots of this paper are available at the Zenodo repository at

Change history


  1. 1.

    Zwanenburg, F. A. et al. Silicon quantum electronics. Rev. Mod. Phys. 85, 961–1019 (2013).

    CAS  Google Scholar 

  2. 2.

    Kloeffel, C. & Loss, D. Prospects for spin-based quantum computing in quantum dots. Annu. Rev. Condens. Matter Phys. 4, 51–81 (2013).

    CAS  Google Scholar 

  3. 3.

    Vandersypen, L. M. K. et al. Interfacing spin qubits in quantum dots and donors: hot, dense, and coherent. npj Quantum Inf. 3, 34 (2017).

    Google Scholar 

  4. 4.

    Scappucci, G. et al. The germanium quantum information route. Preprint at (2020).

  5. 5.

    Tyryshkin, A. M. et al. Electron spin coherence exceeding seconds in high-purity silicon. Nat. Mater. 11, 143–147 (2012).

    CAS  Google Scholar 

  6. 6.

    Yoneda, J. et al. A quantum-dot spin qubit with coherence limited by charge noise and fidelity higher than 99.9%. Nat. Nanotechnol. 13, 102–106 (2018).

    CAS  Google Scholar 

  7. 7.

    Kawakami, E. et al. Electrical control of a long-lived spin qubit in a Si/SiGe quantum dot. Nat. Nanotechnol. 9, 666–670 (2014).

    CAS  Google Scholar 

  8. 8.

    Veldhorst, M. et al. An addressable quantum dot qubit with fault-tolerant control-fidelity. Nat. Nanotechnol. 9, 981–985 (2014).

    CAS  Google Scholar 

  9. 9.

    Veldhorst, M. et al. A two-qubit logic gate in silicon. Nature 526, 410–414 (2015).

    CAS  Google Scholar 

  10. 10.

    Zajac, D. M. et al. Resonantly driven CNOT gate for electron spins. Science 359, 439–442 (2018).

    CAS  Google Scholar 

  11. 11.

    Watson, T. F. et al. A programmable two-qubit quantum processor in silicon. Nature 555, 633–637 (2018).

    CAS  Google Scholar 

  12. 12.

    Hendrickx, N. W., Franke, D. P., Sammak, A., Scappucci, G. & Veldhorst, M. Fast two-qubit logic with holes in germanium. Nature 577, 487–491 (2020).

    CAS  Google Scholar 

  13. 13.

    Loss, D. & DiVincenzo, D. P. Quantum computation with quantum dots. Phys. Rev. A 57, 120–126 (1998).

    CAS  Google Scholar 

  14. 14.

    Bulaev, D. V. & Loss, D. Spin relaxation and decoherence of holes in quantum dots. Phys. Rev. Lett. 95, 076805 (2005).

    Google Scholar 

  15. 15.

    Maurand, R. et al. CMOS silicon spin qubit. Nat. Commun. 7, 13575 (2016).

    CAS  Google Scholar 

  16. 16.

    Crippa, A. et al. Gate-reflectometry dispersive readout and coherent control of a spin qubit in silicon. Nat. Commun. 10, 2776 (2019).

    CAS  Google Scholar 

  17. 17.

    Kloeffel, C., Trif, M. & Loss, D. Strong spin–orbit interaction and helical hole states in Ge/Si nanowires. Phys. Rev. B 84, 195314 (2011).

    Google Scholar 

  18. 18.

    Maier, F., Kloeffel, C. & Loss, D. Tunable g-factor and phonon-mediated hole spin relaxation in Ge/Si nanowire quantum dots. Phys. Rev. B 87, 161305 (2013).

    Google Scholar 

  19. 19.

    Kloeffel, C., Trif, M., Stano, P. & Loss, D. Circuit QED with hole-spin qubits in Ge/Si nanowire quantum dots. Phys. Rev. B 88, 241405 (2013).

    Google Scholar 

  20. 20.

    Kloeffel, C., Rančić, M. J. & Loss, D. Direct Rashba spin–orbit interaction in Si and Ge nanowires with different growth directions. Phys. Rev. B. 97, 235422 (2018).

    CAS  Google Scholar 

  21. 21.

    Yang, C. H. et al. Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting. Nat. Commun. 4, 2069 (2013).

    CAS  Google Scholar 

  22. 22.

    Prechtel, J. H. et al. Decoupling a hole spin qubit from the nuclear spins. Nat. Mater. 15, 981–986 (2016).

    CAS  Google Scholar 

  23. 23.

    Durnev, M. V., Glazov, M. M. & Ivchenko, E. L. Spin–orbit splitting of valence subbands in semiconductor nanostructures. Phys. Rev. B 89, 075430 (2014).

    Google Scholar 

  24. 24.

    Marcellina, E., Hamilton, A. R., Winkler, R. & Culcer, D. Spin–orbit interactions in inversion-asymmetric two-dimensional hole systems: a variational analysis. Phys. Rev. B 95, 075305 (2019).

    Google Scholar 

  25. 25.

    Golovach, V. N., Borhani, M. & Loss, D. Electric-dipole-induced spin resonance in quantum dots. Phys. Rev. B 74, 165319 (2006).

    Google Scholar 

  26. 26.

    Nowack, K. C., Koppens, F. H. L., Nazarov, Y. V. & Vandersypen, L. M. K. Coherent control of a single electron spin with electric fields. Science 318, 1430–1433 (2007).

    CAS  Google Scholar 

  27. 27.

    Bulaev, D. V. & Loss, D. Electric dipole spin resonance for heavy holes in quantum dots. Phys. Rev. Lett. 98, 097202 (2007).

    Google Scholar 

  28. 28.

    van den Berg et al. Fast spin-orbit qubit in an indium antimonide nanowire. Phys. Rev. Lett. 110, 066806 (2013).

    Google Scholar 

  29. 29.

    Pioro-Ladriere, M. et al. Electrically driven single-electron spin resonance in a slanting Zeeman field. Nat. Phys. 4, 776–779 (2008).

    CAS  Google Scholar 

  30. 30.

    Koppens, F. H. L. et al. Driven coherent oscillations of a single electron spin in a quantum dot. Nature 442, 766–771 (2006).

    CAS  Google Scholar 

  31. 31.

    Watzinger, H. et al. A germanium hole spin qubit. Nat. Commun. 9, 3902 (2018).

    Google Scholar 

  32. 32.

    Burkard, G., Gullans, M. J., Mi, X. & Petta, J. R. Superconductor–semiconductor hybrid-circuit quantum electrodynamics. Nat. Rev. Phys. 2, 129–140 (2020).

    Google Scholar 

  33. 33.

    Brauns, M., Ridderbos, J., Li, A., Bakkers, E. P. A. M. & Zwanenburg, F. A. Highly tuneable hole quantum dots in Ge–Si core-shell nanowires. Appl. Phys. Lett. 109, 143113 (2016).

    Google Scholar 

  34. 34.

    Conesa-Boj, S. et al. Boosting hole mobility in coherently strained [110]-oriented Ge–Si core–shell nanowires. Nano Lett. 17, 2259–2264 (2017).

    CAS  Google Scholar 

  35. 35.

    Froning, F. N. M. et al. Single, double, and triple quantum dots in Ge/Si nanowires. Appl. Phys. Lett. 113, 073102 (2018).

    Google Scholar 

  36. 36.

    Ono, K., Austing, D. G., Tokura, Y. & Tarucha, S. Current rectification by Pauli exclusion in a weakly coupled double quantum dot system. Science 297, 1313–1317 (2002).

    CAS  Google Scholar 

  37. 37.

    Yoneda, J. et al. Fast electrical control of single electron spins in quantum dots with vanishing influence from nuclear spins. Phys. Rev. Lett. 113, 267601 (2014).

    CAS  Google Scholar 

  38. 38.

    Takeda, K. et al. S. A fault-tolerant addressable spin qubit in a natural silicon quantum dot. Sci. Adv. 2, e1600694 (2016).

    Google Scholar 

  39. 39.

    Higginbotham, A. P. et al. Hole spin coherence in a Ge/Si heterostructure nanowire. Nano Lett. 14, 3582–3586 (2014).

    CAS  Google Scholar 

  40. 40.

    Hu, Y., Kuemmeth, F., Lieber, C. M. & Marcus, C. M. Hole spin relaxation in Ge–Si core–shell nanowire qubits. Nat. Nanotechnol. 7, 47–50 (2012).

    CAS  Google Scholar 

  41. 41.

    Trif, M., Golovach, V. N. & Loss, D. Spin dynamics in InAs nanowire quantum dots coupled to a transmission line. Phys. Rev. B 77, 045434 (2008).

    Google Scholar 

  42. 42.

    Nigg, S. E., Fuhrer, A. & Loss, D. Superconducting grid-bus surface code architecture for hole-spin qubits. Phys. Rev. Lett. 118, 147701 (2017).

    Google Scholar 

  43. 43.

    Froning, F. N. M. et al. Strong spin–orbit interaction and g-factor renormalization of hole spins in Ge/Si nanowire quantum dots. Preprint at (2020).

  44. 44.

    Higginbotham, A. P. et al. Antilocalization of coulomb blockade in a Ge/Si nanowire. Phys. Rev. Lett. 112, 216806 (2014).

    Google Scholar 

  45. 45.

    Dmytruk, O., Chevallier, D., Loss, D. & Klinovaja, J. Renormalization of the quantum dot g-factor in superconducting Rashba nanowires. Phys. Rev. B 98, 165403 (2018).

    CAS  Google Scholar 

  46. 46.

    Kato, Y. et al. Gigahertz electron spin manipulation using voltage-controlled g-tensor modulation. Science 299, 1201–1204 (2003).

    CAS  Google Scholar 

  47. 47.

    Laucht, A. et al. Breaking the rotating wave approximation for a strongly driven dressed single-electron spin. Phys. Rev. B 94, 161302 (2016).

    Google Scholar 

  48. 48.

    Borjans, F., Croot, X. G., Mi, X., Gullans, M. J. & Petta, J. R. Resonant microwave-mediated interactions between distant electron spins. Nature 577, 195198 (2020).

    Google Scholar 

Download references


We thank S. Bosco, B. Hetényi, C. Kloeffel, D. Loss, A. Laucht and A. Hamilton for useful discussions. Furthermore, we acknowledge S. Martin and M. Steinacher for technical support. This work was partially supported by the Swiss Nanoscience Institute (SNI), the NCCR QSIT, the NCCR SPIN, the Georg H. Endress Foundation, Swiss NSF (grant no. 179024), the EU H2020 European Microkelvin Platform EMP (grant no. 824109) and FET TOPSQUAD (grant no. 862046).

Author information




F.N.M.F., L.C.C., F.R.B. and D.M.Z. conceived the project and experiments. F.N.M.F. fabricated the device. A.L. and E.P.A.M.B. synthesized the nanowire. F.N.M.F., L.C.C., O.A.H.v.d.M., F.R.B. and D.M.Z. performed the experiments. F.N.M.F., L.C.C., F.R.B. and D.M.Z. analysed the measurements and wrote the manuscript with input from all the authors.

Corresponding authors

Correspondence to Dominik M. Zumbühl or Floris R. Braakman.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Nanotechnology thanks the anonymous reviewers for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Notes 1 and 2, Figs. 1–4 and Table 1.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Froning, F.N.M., Camenzind, L.C., van der Molen, O.A.H. et al. Ultrafast hole spin qubit with gate-tunable spin–orbit switch functionality. Nat. Nanotechnol. 16, 308–312 (2021).

Download citation

Further reading


Quick links

Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research