Hybrid superconductor–semiconductor devices made from self-assembled SiGe nanocrystals on silicon

Abstract

The epitaxial growth of germanium on silicon leads to the self-assembly of SiGe nanocrystals by a process that allows the size, composition and position of the nanocrystals to be controlled. This level of control, combined with an inherent compatibility with silicon technology, could prove useful in nanoelectronic applications. Here, we report the confinement of holes in quantum-dot devices made by directly contacting individual SiGe nanocrystals with aluminium electrodes, and the production of hybrid superconductor–semiconductor devices, such as resonant supercurrent transistors, when the quantum dot is strongly coupled to the electrodes. Charge transport measurements on weakly coupled quantum dots reveal discrete energy spectra, with the confined hole states displaying anisotropic gyromagnetic factors and strong spin–orbit coupling with pronounced dependences on gate voltage and magnetic field.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Structure and growth of SiGe self-assembled nanocrystals and device layout.
Figure 2: SiGe single-hole supercurrent transistor.
Figure 3: Tunnelling spectroscopy measurements on a high-resistance device.
Figure 4: Anisotropy and gate dependence of the hole g-factors.
Figure 5: Anisotropic spin–orbit coupling strength probed by inelastic co-tunnelling.

References

  1. 1

    Javey, A., Guo, J., Wang, Q., Lundstrom, M. & Dai, H. J. Ballistic carbon nanotube field-effect transistors. Nature 424, 654–657 (2003).

    CAS  Article  Google Scholar 

  2. 2

    Xiang, J. et al. Ge/Si nanowire heterostructures as high-performance field-effect transistors. Nature 441, 489–493 (2006).

    CAS  Article  Google Scholar 

  3. 3

    Ryu, K. et al. CMOS-analogous wafer-scale nanotube-on-insulator approach for submicrometer devices and integrated circuits using aligned nanotubes. Nano Lett. 9, 189–197 (2009).

    CAS  Article  Google Scholar 

  4. 4

    Nam, S. W., Jiang, X., Xiong, Q., Ham, D. & Lieber C. M. Vertically integrated, three-dimensional complementary metal-oxide–semiconductor circuits. Proc. Natl Acad. Sci. USA 106, 21035–21038 (2009).

    CAS  Article  Google Scholar 

  5. 5

    Eaglesham, D. J. & Cerullo, M. Dislocation-free Stranski–Krastanow growth of Ge on Si(100). Phys. Rev. Lett. 64, 1943–1946 (1990).

    CAS  Article  Google Scholar 

  6. 6

    Mo, Y. W., Savage, D. E., Swartzenruber, B. S. & Lagally M. G. Kinetic pathway in Stranski–Krastanov growth of Ge on Si(001). Phys. Rev. Lett. 65, 1020–1023 (1990).

    CAS  Article  Google Scholar 

  7. 7

    Medeiros-Ribeiro, G. et al. Shape transition of germanium nanocrystals on a silicon (001) surface from pyramids to domes. Science 279, 353–355 (1998).

    CAS  Article  Google Scholar 

  8. 8

    Stangl, J., Holý, V. & Bauer, G. Structural properties of self-organized semiconductor nanostructures. Rev. Mod. Phys. 76, 725–783 (2004).

    CAS  Article  Google Scholar 

  9. 9

    Katsaros, G. et al. Kinetic origin of island intermixing during the growth of Ge on Si(001). Phys. Rev. B 72, 195320 (2005).

    Article  Google Scholar 

  10. 10

    Schmidt, O. G. (ed.). Lateral Alignment of Epitaxial Quantum Dots (Springer, 2007).

    Google Scholar 

  11. 11

    Katsaros, G. et al. Positioning of strained islands by interaction with surface nanogrooves. Phys. Rev. Lett. 101, 096103 (2008).

    CAS  Article  Google Scholar 

  12. 12

    Schmidt, O. G. & Eberl, K. Self-assembled Ge/Si dots for faster field effect transistors. IEEE Trans. Electron Dev. 48, 1175–1179 (2001).

    CAS  Article  Google Scholar 

  13. 13

    Xiang, J., Vidan, A., Tinkham, M., Westervelt, R. M. & Lieber C. M. Ge/Si nanowire mesoscopic Josephson junctions. Nature Nanotech. 1, 208–213 (2006).

    CAS  Article  Google Scholar 

  14. 14

    Hu, Y. A Ge/Si heterostructure nanowire-based double quantum dot with integrated charge sensor. Nature Nanotech. 2, 622–625 (2007).

    CAS  Article  Google Scholar 

  15. 15

    Shaji, N. et al. Spin blockade and lifetime-enhanced transport in a few-electron Si/SiGe double quantum dot. Nature Phys. 4, 540–544 (2008).

    CAS  Article  Google Scholar 

  16. 16

    Simmons, C. B. et al. Charge sensing and controllable tunnel coupling in a Si/SiGe double quantum dot. Nano Lett. 9, 3234–3238 (2009).

    CAS  Article  Google Scholar 

  17. 17

    Hayes, R. R. et al. Lifetime measurements (T1) of electron spins in Si/SiGe quantum dots. Preprint at http://arxiv.org/abs/0908.0173 (2009).

  18. 18

    Dötsch, U. et al. Single-hole transistor in p-Si/SiGe quantum well. Appl. Phys. Lett. 78, 341–343 (2001).

    Article  Google Scholar 

  19. 19

    Petta, J. R. & Ralph, D. C. Studies of spin–orbit scattering in noble-metal nanoparticles using energy-level tunneling spectroscopy. Phys. Rev. Lett. 87, 266801 (2001).

    CAS  Article  Google Scholar 

  20. 20

    Winkler, R. Spin–Orbit Coupling Effect in Two-Dimensional Electron and Hole Systems (Springer, 2004).

    Google Scholar 

  21. 21

    Csonka, S. et al. Giant fluctuations and gate control of the g-factor in InAs nanowire quantum dots. Nano Lett. 8, 3932–3935 (2008).

    CAS  Article  Google Scholar 

  22. 22

    Nilson, H. A. et al. Giant, level-dependent g factors in InSb nanowire quantum dots. Nano Lett. 9, 3151–3156 (2009).

    Article  Google Scholar 

  23. 23

    Salis, G. et al. Electrical control of spin coherence in semiconductor nanostructures. Nature 414, 619–622 (2001).

    CAS  Article  Google Scholar 

  24. 24

    Roddaro, S. et al. Spin states of holes in Ge/Si nanowire quantum dots. Phys. Rev. Lett. 101, 186802 (2008).

    CAS  Article  Google Scholar 

  25. 25

    Jung, M. et al. Lateral electron transport through single self-assembled InAs quantum dots. Appl. Phys. Lett. 86, 033106 (2005).

    Article  Google Scholar 

  26. 26

    Hamaya, K. et al. Kondo effect in a semiconductor quantum dot coupled to ferromagnetic electrodes. Appl. Phys. Lett. 91, 232105 (2007).

    Article  Google Scholar 

  27. 27

    Buizert, C., Oiwa, A., Shibata, K., Hirakawa, K. & Tarucha, S. Kondo universal scaling for a quantum dot coupled to superconducting leads. Phys. Rev. Lett. 99, 136806 (2007).

    CAS  Article  Google Scholar 

  28. 28

    Glazman, L. I. & Matveev, K. A. Resonant Josephson current through Kondo impurities in a tunnel barrier. JETP Lett. 49, 659–662 (1989).

    Google Scholar 

  29. 29

    Beenakker, C. W. J. & van Houten, H. Resonant Josephson current through a quantum dot, in Single-Electron Tunneling and Mesoscopic Devices (eds Koch, H. & Lübbig, H.) 175–179 (Springer, 1992), http://arxiv.org/abs/cond-mat/0111505.

    Google Scholar 

  30. 30

    Jarillo-Herrero, P., van Dam, J. A. & Kouwenhoven, L. P. Quantum supercurrent transistors in carbon nanotubes. Nature 439, 953–956 (2006).

    CAS  Article  Google Scholar 

  31. 31

    Cleuziou, J.-P., Wernsdorfer, W., Bouchiat, V., Ondarçuhu, T. & Monthioux, M. Carbon nanotube superconducting quantum interference device. Nature Nanotech. 1, 53–59 (2006).

    CAS  Article  Google Scholar 

  32. 32

    van Dam, J. A., Nazarov, Y. V., Bakkers, E. P. A. M., De Franceschi, S. & Kouwenhoven, L. P. Supercurrent reversal in quantum dots. Nature 442, 667–670 (2006).

    CAS  Article  Google Scholar 

  33. 33

    Winkelmann, C. B., Roch, N., Wernsdorfer, W. Bouchiat, V. & Balestro, F. Superconductivity in a single-C60 transistor. Nature Phys. 5, 876–879 (2009).

    CAS  Article  Google Scholar 

  34. 34

    Nenashev, A. V., Dvurechenskii, A. V. & Zinovieva, A. F. Wave functions and g factor of holes in Ge/Si quantum dots. Phys. Rev. B 67, 205301 (2003).

    Article  Google Scholar 

  35. 35

    Hensel, J. C. & Suzuki, K. Anisotropy of g factor of free hole in Ge and conduction-band spin–orbit splitting. Phys. Rev. Lett. 22, 838–840 (1969).

    CAS  Article  Google Scholar 

  36. 36

    Haendel, K.-M., Winkler, R., Denker, U., Schmidt, O. G. & Haug, R. J. Giant anisotropy of Zeeman splitting of quantum confined acceptors in Si/Ge. Phys. Rev. Lett. 96, 086403 (2006).

    Article  Google Scholar 

  37. 37

    De Franceschi, S. et al. Electron cotunneling in a semiconductor quantum dot. Phys. Rev. Lett. 86, 878–881 (2001).

    CAS  Article  Google Scholar 

  38. 38

    Buitelaar, M. R. et al. Multiple Andreev reflections in a carbon nanotube quantum dot. Phys. Rev. Lett. 91, 057005 (2003).

    CAS  Article  Google Scholar 

  39. 39

    Hanson, R., Kouwenhoven, L. P., Petta, J. R., Tarucha, S. & Vandersypen, L. M. K. Spins in few-electron quantum dots. Rev. Mod. Phys. 79, 1217–1265 (2007).

    CAS  Article  Google Scholar 

  40. 40

    Nitta, J., Akazaki, T., Takayanagi, H. & Enoki, T. Gate control of spin–orbit interaction in an inverted In0.53Ga0.47As/In0.52Al0.48As heterostructure. Phys. Rev. Lett. 78, 1335–1338 (1997).

    CAS  Article  Google Scholar 

  41. 41

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

    Article  Google Scholar 

  42. 42

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

    CAS  Article  Google Scholar 

  43. 43

    Frolov, S. M. et al. Ballistic spin resonance. Nature 458, 868–871 (2009).

    CAS  Article  Google Scholar 

  44. 44

    Fasth, C., Fuhrer, A., Samuelson, L., Golovach, V. N. & Loss, D. Direct measurement of the spin–orbit interaction in a two-electron InAs nanowire quantum dot. Phys. Rev. Lett. 98, 266801 (2007).

    CAS  Article  Google Scholar 

  45. 45

    Roch, N., Florens, S., Bouchiat, V., Wernsdorfer, W. & Balestro, F. Quantum phase transition in a single-molecule quantum dot. Nature 453, 633–638 (2008).

    CAS  Article  Google Scholar 

  46. 46

    Golovach, V. N., Khaetskii, A. & Loss, D. Spin relaxation at the singlet–triplet crossing in a quantum dot. Phys. Rev. B 77, 045328 (2008).

    Article  Google Scholar 

  47. 47

    Takahashi, S. et al. Large anisotropy of spin–orbit interaction in a single InAs self-assembled quantum dot. Preprint at http://arxiv.org/abs/0912.3088 (2009).

  48. 48

    Pasupathy, A. N. et al. The Kondo effect in the presence of ferromagnetism. Science 306, 86–89 (2004).

    CAS  Article  Google Scholar 

  49. 49

    Hauptmann, J. R., Paaske, J. & Lindelof P. E. Electric-field-controlled spin reversal in a quantum dot with ferromagnetic contacts. Nature Phys. 4, 373–376 (2008).

    CAS  Article  Google Scholar 

  50. 50

    Zazunov, A., Egger, R., Jonckheere, T. & Martin, T. Anomalous Josephson current through a spin–orbit coupled quantum dot. Phys. Rev. Lett. 103, 147004 (2009).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

The authors thank T. Haccart and the PTA cleanroom team of CEA, J.-L. Thomassin and F. Gustavo for their help in device fabrication, and T. Fournier for helpful discussions and providing free access to fabrication recipes and equipment at the NANOFAB facility of the Néel Institute. We also acknowledge helpful discussions with M. Houzet, V. Golovach, W. Wernsdorfer, D. Feinberg, G. Usaj, R. Whitney, M. Sanquer, X. Jehl, G. A. Steele and E. J. H. Lee, and support from the Agence Nationale de la Recherche (through the ACCESS and COHESION projects). G.K. acknowledges further support from the Deutsche Forschungsgemeinschaft (grant no. KA 2922/1-1).

Author information

Affiliations

Authors

Contributions

G.K. and S.D.F. planned the experiment, interpreted the data and co-wrote the paper. G.K. fabricated the devices, performed the measurements with P.S. and S.D.F., and analysed the data. P.S. participated in the data analysis and set up the dilution refrigerator. M.S. grew the SiGe self-assembled nanocrystal samples. F.F. fabricated the non-standard SOI wafers. M.M., V.B. and F.L. provided important help in device fabrication. A.R. and O.G.S. supervised the growth of the self-assembled SiGe nanocrystals. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to G. Katsaros or S. De Franceschi.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 481 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Katsaros, G., Spathis, P., Stoffel, M. et al. Hybrid superconductor–semiconductor devices made from self-assembled SiGe nanocrystals on silicon. Nature Nanotech 5, 458–464 (2010). https://doi.org/10.1038/nnano.2010.84

Download citation

Further reading