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Supercurrent reversal in quantum dots

Nature volume 442, pages 667–670 (2006)Cite this article

Abstract

When two superconductors are electrically connected by a weak link—such as a tunnel barrier—a zero-resistance supercurrent can flow1,2. This supercurrent is carried by Cooper pairs of electrons with a combined charge of twice the elementary charge, e. The 2e charge quantum is clearly visible in the height of voltage steps in Josephson junctions under microwave irradiation, and in the magnetic flux periodicity of h/2e (where h is Planck's constant) in superconducting quantum interference devices2. Here we study supercurrents through a quantum dot created in a semiconductor nanowire by local electrostatic gating. Owing to strong Coulomb interaction, electrons only tunnel one-by-one through the discrete energy levels of the quantum dot. This nevertheless can yield a supercurrent when subsequent tunnel events are coherent3,4,5,6,7. These quantum coherent tunnelling processes can result in either a positive or a negative supercurrent, that is, in a normal or a π-junction8,9,10, respectively. We demonstrate that the supercurrent reverses sign by adding a single electron spin to the quantum dot. When excited states of the quantum dot are involved in transport, the supercurrent sign also depends on the character of the orbital wavefunctions.

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Figure 1: Sample layout and device characterization.
Figure 2: Supercurrent reversal in an interacting quantum dot.
Figure 3: Energy diagrams illustrating Cooper pair transport through a quantum dot due to fourth-order co-tunnelling.
Figure 4: Experimental results and numerical simulations for a multi-level quantum dot.

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References

  1. Josephson, B. D. Possible new effects in superconductive tunnelling. Phys. Lett. 1, 251–253 (1962)

    Article  ADS  Google Scholar 

  2. Tinkham, M. Introduction to Superconductivity 2nd edn (McGraw-Hill, Singapore, 1996)

    Google Scholar 

  3. Bulaevskii, L. N., Kuzii, V. V. & Sobyanin, A. A. Superconducting system with weak coupling to the current in the ground state. JETP Lett. 25, 290–294 (1977)

    ADS  Google Scholar 

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

    ADS  Google Scholar 

  5. Spivak, B. I. & Kivelson, S. A. Negative local superfluid densities: The difference between dirty superconductors and dirty Bose liquids. Phys. Rev. B 43, 3740–3743 (1991)

    Article  ADS  CAS  Google Scholar 

  6. Bauernschmitt, R., Siewert, J., Nazarov, Yu. V. & Odintsov, A. A. Josephson effect in low-capacitance superconductor–normal-metal–superconductor systems. Phys. Rev. B 49, 4076–4081 (1994)

    Article  ADS  CAS  Google Scholar 

  7. Rozhkov, A. V., Arovas, D. P. & Guinea, F. Josephson coupling through a quantum dot. Phys. Rev. B 64, 233301 (2001)

    Article  ADS  Google Scholar 

  8. van Harlingen, D. J. Phase-sensitive tests of the symmetry of the pairing state in the high-temperature superconductors - Evidence for dx2-y2 symmetry. Rev. Mod. Phys. 67, 515–535 (1995)

    Article  ADS  CAS  Google Scholar 

  9. Ryazanov, V. V. et al. Coupling of two superconductors through a ferromagnet: Evidence for a π-junction. Phys. Rev. Lett. 86, 2427–2430 (2001)

    Article  ADS  CAS  PubMed  Google Scholar 

  10. Baselmans, J. J. A., Morpurgo, A. F., van Wees, B. J. & Klapwijk, T. M. Reversing the direction of the supercurrent in a controllable Josephson junction. Nature 397, 43–45 (1999)

    Article  ADS  CAS  Google Scholar 

  11. Ralph, D. C., Black, C. T. & Tinkham, M. Spectroscopic measurements of discrete electronic states in single metal particles. Phys. Rev. Lett. 74, 3241–3244 (1995)

    Article  ADS  CAS  Google Scholar 

  12. Black, C. T., Ralph, D. C. & Tinkham, M. Spectroscopy of the superconducting gap in individual nanometer-scale aluminum particles. Phys. Rev. Lett. 76, 688–691 (1996)

    Article  ADS  CAS  PubMed  Google Scholar 

  13. Buitelaar, M. R., Nussbaumer, T. & Schönenberger, C. Quantum dot in the Kondo regime coupled to superconductors. Phys. Rev. Lett. 89, 256801 (2002)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  PubMed  Google Scholar 

  16. Doh, Y. J. et al. Tunable supercurrent through semiconductor nanowires. Science 309, 272–275 (2005)

    Article  ADS  CAS  Google Scholar 

  17. Wagner, R. S. & Ellis, W. C. Vapor-liquid-solid mechanism of single crystal growth. Appl. Phys. Lett. 4, 89–90 (1964)

    Article  ADS  CAS  Google Scholar 

  18. Morales, A. M. & Lieber, C. M. A laser ablation method for the synthesis of crystalline semiconductor nanowires. Science 279, 208–211 (1998)

    Article  ADS  CAS  Google Scholar 

  19. Björk, M. T. et al. One-dimensional heterostructures in semiconductor nanowhiskers. Appl. Phys. Lett. 80, 1058–1060 (2002)

    Article  ADS  Google Scholar 

  20. Verheijen, M. A., Immink, G., de Smet, T., Borgström, M. T. & Bakkers, E. P. A. M. Growth kinetics of heterostructured GaP-GaAs nanowires. J. Am. Chem. Soc. 128, 1353–1359 (2006)

    Article  CAS  PubMed  Google Scholar 

  21. Sohn, L. L., Kouwenhoven, L. P. & Schön, G. (eds) Mesoscopic Electron Transport (Kluwer, Dordrecht, 1997)

  22. Baselmans, J. J. A., Heikkilä, T. T., van Wees, B. J. & Klapwijk, T. M. Direct observation of the transition from the conventional superconducting state to the π state in a controllable Josephson junction. Phys. Rev. Lett. 89, 207002 (2002)

    Article  ADS  CAS  PubMed  Google Scholar 

  23. Averin, D. V. & Nazarov, Y. V. in Single Charge Tunneling (eds Grabert, H. & Devoret, M. H.) Proc. NATO ASI Ser. B 294 217–247 (Plenum, New York, 1991)

    Google Scholar 

  24. Björk, M. T. et al. Tunable effective g factor in InAs nanowire quantum dots. Phys. Rev. B 72, 201307 (2005)

    Article  ADS  Google Scholar 

  25. Shimizu, Y., Horii, H., Takane, Y. & Isawa, Y. Multilevel effect on the Josephson current through a quantum dot. J. Phys. Soc. Jpn 67, 1525–1528 (1998)

    Article  ADS  CAS  Google Scholar 

  26. Goldhaber-Gordon, D. et al. Kondo effect in a single-electron transistor. Nature 391, 156–159 (1998)

    Article  ADS  CAS  Google Scholar 

  27. Cronenwett, S. M., Oosterkamp, T. H. & Kouwenhoven, L. P. A tunable Kondo effect in quantum dots. Science 281, 540–544 (1998)

    Article  ADS  CAS  PubMed  Google Scholar 

  28. Choi, M. S., Lee, M., Kang, K. & Belzig, W. Kondo effect and Josephson current through a quantum dot between two superconductors. Phys. Rev. B 70, 020502 (2004)

    Article  ADS  Google Scholar 

  29. Siano, F. & Egger, R. Josephson current through a nanoscale magnetic quantum dot. Phys. Rev. Lett. 93, 047002 (2004)

    Article  ADS  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

We thank Y.-J. Doh and L. Glazman for discussions, G. Immink for nanowire growth, and A. van der Enden and R. Schouten for technical support. Financial support was obtained from the Dutch Foundation for Fundamental Research on Matter (FOM), the Dutch Organisation for Scientific Research (NWO), the EU programmes HYSWITCH and NODE, and the Japanese International Cooperative Research Project (ICORP). Author Contributions J.A.v.D., S.D.F. and L.P.K. are responsible for quantum transport experiments, Y.V.N. for numerical simulations, and E.P.A.M.B. for nanowire growth.

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Authors and Affiliations

  1. Kavli Institute of Nanoscience, Delft University of Technology, Delft, PO Box 5046, 2600 GA, The Netherlands

    Jorden A. van Dam, Yuli V. Nazarov, Silvano De Franceschi & Leo P. Kouwenhoven

  2. Philips Research Laboratories, Eindhoven, High Tech Campus 4, 5656 AE, The Netherlands

    Erik P. A. M. Bakkers

  3. Laboratorio Nazionale TASC INFM-CNR, Area Science Park, Trieste, S.S. 14, Km. 163.5, I-34012, Italy

    Silvano De Franceschi

Authors
  1. Jorden A. van Dam
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  2. Yuli V. Nazarov
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  4. Silvano De Franceschi
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  5. Leo P. Kouwenhoven
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Correspondence to Leo P. Kouwenhoven.

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Supplementary information

Supplementary Notes

This file contains Supplementary Methods (nanowire growth and device fabrication), Supplementary Data (data for a seconds device), Supplementary Discussion (supercurrent reversal) and Supplementary Methods (numerical evaluation of supercurrents). (DOC 122 kb)

Supplementary Figure 1

Scanning Electron Microscopy images. (PDF 758 kb)

Supplementary Figure 2

Supercurrent reversal in the second device. (PDF 102 kb)

Supplementary Figure 3

Energy diagrams illustrating transport through a multi-level quantum dot. (PDF 85 kb)

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van Dam, J., Nazarov, Y., Bakkers, E. et al. Supercurrent reversal in quantum dots. Nature 442, 667–670 (2006). https://doi.org/10.1038/nature05018

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