Skip to main content

Thank you for visiting nature.com. 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.

  • Article
  • Published:

Ultrafast terahertz control of extreme tunnel currents through single atoms on a silicon surface

Nature Physics volume 13, pages 591–598 (2017)Cite this article

Subjects

Abstract

Ultrafast control of current on the atomic scale is essential for future innovations in nanoelectronics. Extremely localized transient electric fields on the nanoscale can be achieved by coupling picosecond duration terahertz pulses to metallic nanostructures. Here, we demonstrate terahertz scanning tunnelling microscopy (THz-STM) in ultrahigh vacuum as a new platform for exploring ultrafast non-equilibrium tunnelling dynamics with atomic precision. Extreme terahertz-pulse-driven tunnel currents up to 107 times larger than steady-state currents in conventional STM are used to image individual atoms on a silicon surface with 0.3 nm spatial resolution. At terahertz frequencies, the metallic-like Si(111)-(7 × 7) surface is unable to screen the electric field from the bulk, resulting in a terahertz tunnel conductance that is fundamentally different than that of the steady state. Ultrafast terahertz-induced band bending and non-equilibrium charging of surface states opens new conduction pathways to the bulk, enabling extreme transient tunnel currents to flow between the tip and sample.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Control of extreme tunnel currents with THz-STM in ultrahigh vacuum.
Figure 2: Imaging silicon atoms with terahertz-driven scanning tunnelling microscopy (TD-STM).
Figure 3: Modelling TD-STM on Si(111)-(7 × 7) in the extreme tunnel current regime.
Figure 4: Ultrafast control of non-equilibrium tunnelling through single atoms on Si(111)-(7 × 7).
Figure 5: Electric field spatial profiles obtained from 3D electromagnetic simulations.
Figure 6: Hot electrons in the terahertz-induced current.

Similar content being viewed by others

References

  1. Völcker, M., Krieger, W. & Walther, H. Laser-driven scanning tunneling microscope. Phys. Rev. Lett. 66, 1717–1720 (1991).

    Article  ADS  Google Scholar 

  2. Lee, J., Long, C. J., Yang, H., Xiang, X.-D. & Takeuchi, I. Atomic resolution imaging at 2.5 GHz using near-field microwave microscopy. Appl. Phys. Lett. 97, 183111 (2010).

    Article  ADS  Google Scholar 

  3. Cocker, T. L. et al. An ultrafast terahertz scanning tunnelling microscope. Nat. Photon. 7, 620–625 (2013).

    Article  ADS  Google Scholar 

  4. Cocker, T. L., Peller, D., Yu, P., Repp, J. & Huber, R. Tracking the ultrafast motion of a single molecule by femtosecond orbital imaging. Nature 539, 263–267 (2016).

    Article  ADS  Google Scholar 

  5. Yoshioka, K. et al. Real-space coherent manipulation of electrons in a single tunnel junction by single-cycle terahertz electric fields. Nat. Photon. 10, 762–765 (2016).

    Article  ADS  Google Scholar 

  6. Khusnatdinov, N. N., Nagle, T. J. & Nunes, G. Jr Ultrafast scanning tunneling microscopy with 1 nm resolution. Appl. Phys. Lett. 77, 4434–4436 (2000).

    Article  ADS  Google Scholar 

  7. Grafström, S. Photoassisted scanning tunneling microscopy. J. Appl. Phys. 91, 1717–1753 (2002).

    Article  ADS  Google Scholar 

  8. Loth, S., Etzkorn, M., Lutz, C. P., Eigler, D. M. & Heinrich, A. J. Measurement of fast electron spin relaxation times with atomic resolution. Science 329, 1628–1630 (2010).

    Article  ADS  Google Scholar 

  9. Wu, S. W. & Ho, W. Two-photon-induced hot-electron transfer to a single molecule in a scanning tunneling microscope. Phys. Rev. B 82, 085444 (2010).

    Article  ADS  Google Scholar 

  10. Saunus, C., Bindel, J. R., Pratzer, M. & Morgenstern, M. Versatile scanning tunneling microscopy with 120 ps time resolution. Appl. Phys. Lett. 102, 051601 (2013).

    Article  ADS  Google Scholar 

  11. Yoshida, S. et al. Single-atomic-level probe of transient carrier dynamics by laser-combined scanning tunneling microscopy. Appl. Phys. Express 6, 032401 (2013).

    Article  ADS  Google Scholar 

  12. Yoshida, S. et al. Probing ultrafast spin dynamics with optical pump–probe scanning tunnelling microscopy. Nat. Nanotech. 9, 588–593 (2014).

    Article  ADS  Google Scholar 

  13. Dey, S., Mirell, D., Rodriguez Perez, A., Lee, J. & Apkarian, V. A. Nonlinear femtosecond laser induced scanning tunneling microscopy. J. Chem. Phys. 138, 154202 (2013).

    Article  ADS  Google Scholar 

  14. Lee, J., Perdue, S. M., Rodriguez Perez, A. & Apkarian, V. A. Vibronic motion with joint angstrom–femtosecond resolution observed through Fano progressions recorded within one molecule. ACS Nano 8, 54–63 (2014).

    Article  Google Scholar 

  15. Rashidi, M. et al. Time-resolved single dopant charge dynamics in silicon. Nat. Commun. 7, 13258 (2016).

    Article  ADS  Google Scholar 

  16. Kampfrath, T., Tanaka, K. & Nelson, K. A. Resonant and nonresonant control over matter and light by intense terahertz transients. Nat. Photon. 7, 680–690 (2013).

    Article  ADS  Google Scholar 

  17. Wimmer, L. et al. Terahertz control of nanotip photoemission. Nat. Phys. 10, 432–436 (2014).

    Article  Google Scholar 

  18. Herink, G., Wimmer, L. & Ropers, C. Field emission at terahertz frequencies: AC-tunneling and ultrafast carrier dynamics. New J. Phys. 16, 123005 (2014).

    Article  ADS  Google Scholar 

  19. Li, S. & Jones, R. R. High-energy electron emission from metallic nano-tips driven by intense single-cycle terahertz pulses. Nat. Commun. 7, 13405 (2016).

    Article  ADS  Google Scholar 

  20. Iwaszczuk, K., Zalkovskij, M., Strikwerda, A. C. & Jepsen, P. U. Nitrogen plasma formation through terahertz-induced ultrafast electron field emission. Optica 2, 116–123 (2015).

    Article  Google Scholar 

  21. Mittleman, D. M. Frontiers in terahertz sources and plasmonics. Nat. Photon. 7, 666–669 (2013).

    Article  ADS  Google Scholar 

  22. Huber, A. J., Keilmann, F., Wittborn, J., Aizpurua, J. & Hillenbrand, R. Terahertz near-field nanoscopy of mobile carriers in single semiconductor nanodevices. Nano Lett. 8, 3766–3770 (2008).

    Article  ADS  Google Scholar 

  23. Eisele, M. et al. Ultrafast multi-terahertz nano-spectroscopy with sub-cycle temporal resolution. Nat. Photon. 8, 841–845 (2014).

    Article  ADS  Google Scholar 

  24. Chen, C. J. Introduction to Scanning Tunneling Microscopy 2nd edn (Oxford Univ. Press, 2008).

    Google Scholar 

  25. Voigtländer, B. Scanning Probe Microscopy (Springer, 2015).

    Google Scholar 

  26. Chen, C. J. Microscopic view of scanning tunneling microscopy. J. Vac. Sci. Technol. A 9, 44–50 (1990).

    Article  ADS  Google Scholar 

  27. Hamers, R. J., Tromp, R. M. & Demuth, J. E. Surface electronic structure of Si(111)-(7 × 7) resolved in real space. Phys. Rev. Lett. 56, 1972–1975 (1986).

    Article  ADS  Google Scholar 

  28. Krause, S., Berbil-Bautista, L., Herzog, G., Bode, M. & Wiesendanger, R. Current-induced magnetization switching with a spin-polarized scanning tunneling microscope. Science 317, 1537–1540 (2007).

    Article  ADS  Google Scholar 

  29. Hasunuma, R., Komeda, T., Mukaida, H. & Tokumoto, H. Atom manipulation on Si(111)-7 × 7 surface by contact formation of biased scanning tunneling microscope tip: surface structures and tip current variation with atom removal. J. Vac. Sci. Technol. A 15, 1482–1487 (1997).

    Article  ADS  Google Scholar 

  30. Mysliveček, J. et al. Structure of the adatom electron band of the Si(111)-7 × 7 surface. Phys. Rev. B 73, 161302 (2006).

    Article  ADS  Google Scholar 

  31. Modesti, S., Gutzmann, H., Wiebe, J. & Wiesendanger, R. Correction of systematic errors in scanning tunneling spectra on semiconductor surfaces: the energy gap of Si(111)-7 × 7 at 0.3 K. Phys. Rev. B 80, 125326 (2009).

    Article  ADS  Google Scholar 

  32. Liao, Y. C. et al. Evolution of surface to bulk tunneling spectrum by scanning tunneling microscopy. Phys. Rev. B 81, 195435 (2010).

    Article  ADS  Google Scholar 

  33. Feenstra, R. M., Gaan, S., Meyer, G. & Rieder, K. H. Low-temperature tunneling spectroscopy of Ge(111)c(2 × 8) surfaces. Phys. Rev. B 71, 125316 (2005).

    Article  ADS  Google Scholar 

  34. Wutscher, T., Weymouth, A. J. & Giessibl, F. J. Localization of the phantom force induced by the tunneling current. Phys. Rev. B 85, 195426 (2012).

    Article  ADS  Google Scholar 

  35. Taucer, M. et al. Single-electron dynamics of an atomic silicon quantum dot on the H-Si(100)-(2 × 1) surface. Phys. Rev. Lett. 112, 256801 (2014).

    Article  ADS  Google Scholar 

  36. Martins, B. V. C., Smeu, M., Livadaru, L., Guo, H. & Wolkow, R. A. Conductivity of Si(111)-(7 × 7): the role of a single atomic step. Phys. Rev. Lett. 112, 246802 (2014).

    Article  ADS  Google Scholar 

  37. Just, S. et al. Surface and step conductivities on Si(111) surfaces. Phys. Rev. Lett. 115, 066801 (2015).

    Article  ADS  Google Scholar 

  38. Lock, D., Rusimova, K. R., Pan, T. L., Palmer, R. E. & Sloan, P. A. Atomically resolved real-space imaging of hot electron dynamics. Nat. Commun. 6, 8365 (2015).

    Article  ADS  Google Scholar 

  39. Odobescu, A. B., Maizlakh, A. A. & Zaitsev-Zotov, S. V. Electron correlation effects in transport and tunneling spectroscopy of the Si(111)-7 × 7 surface. Phys. Rev. B 92, 165313 (2015).

    Article  ADS  Google Scholar 

  40. Ortega, J., Flores, F. & Levy Yeyati, A. Electron correlation effects in the Si(111)-7 × 7 surface. Phys. Rev. B 58, 4584–4588 (1998).

    Article  ADS  Google Scholar 

  41. Losio, R., Altmann, K. N. & Himpsel, F. J. Fermi surface of Si(111)7 × 7. Phys. Rev. B 61, 10845–10853 (2000).

    Article  ADS  Google Scholar 

  42. Tanikawa, T., Yoo, K., Matsuda, I., Hasegawa, S. & Hasegawa, Y. Nonmetallic transport property of the Si(111)7 × 7 surface. Phys. Rev. B 68, 113303 (2003).

    Article  ADS  Google Scholar 

  43. Barke, I., Zheng, F., Konicek, A. R., Hatch, R. C. & Himpsel, F. J. Electron-phonon interaction at the Si(111)-7 × 7 surface. Phys. Rev. Lett. 96, 216801 (2006).

    Article  ADS  Google Scholar 

  44. Mauerer, M., Shumay, I. L., Berthold, W. & Höfer, U. Ultrafast carrier dynamics in Si(111)7 × 7 dangling bonds probed by time-resolved second-harmonic generation and two-photon photoemission. Phys. Rev. B 73, 245305 (2006).

    Article  ADS  Google Scholar 

  45. Wells, J. W., Kallehauge, J. F., Hansen, T. M. & Hofmann, P. Disentangling surface, bulk, and space-charge-layer conductivity in Si(111)-(7 × 7). Phys. Rev. Lett. 97, 206803 (2006).

    Article  ADS  Google Scholar 

  46. D’angelo, M. et al. Conductivity of the Si(111)7 × 7 dangling-bond state. Phys. Rev. B 79, 035318 (2009).

    Article  ADS  Google Scholar 

  47. Nguyen, P. H. et al. Coupling terahertz pulses to a scanning tunneling microscope. Phys. Can. 71, 157–160 (2015).

    Google Scholar 

  48. Baccarani, G. & Ostoja, P. Electron mobility empirically related to the phosphorus concentration in silicon. Solid-State Electron. 18, 579–580 (1975).

    Article  ADS  Google Scholar 

  49. Rybka, T. et al. Sub-cycle optical phase control of nanotunnelling in the single-electron regime. Nat. Photon. 10, 667–670 (2016).

    Article  ADS  Google Scholar 

  50. Rashidi, M. et al. Time-resolved imaging of negative differential resistance on the atomic scale. Phys. Rev. Lett. 117, 276805 (2016).

    Article  Google Scholar 

  51. Feenstra, R. M. & Stroscio, J. Tunneling spectroscopy of the GaAs(110) surface. J. Vac. Sci. Technol. B 5, 923–929 (1987).

    Article  Google Scholar 

  52. Hamers, R. J., Tromp, R. M. & Demuth, J. E. Electronic and geometric structure of Si(111)-(7 × 7) and Si(001) surfaces. Surf. Sci. 181, 346–355 (1987).

    Article  ADS  Google Scholar 

  53. Güntherodt, H.-J. & Wiesendanger, R. (eds) Scanning Tunneling Microscopy I (Springer, 1992).

  54. Wiesendanger, R. Scanning Probe Microscopy and Spectroscopy: Methods and Applications (Cambridge Univ. Press, 1994).

    Book  Google Scholar 

  55. Lee, Y.-S. Principles of Terahertz Science and Technology (Springer, 2008).

    Google Scholar 

  56. Blanchard, F., Doi, A., Tanaka, T. & Tanaka, K. Real-time, subwavelength terahertz imaging. Annu. Rev. Mater. Res. 43, 237–259 (2013).

    Article  ADS  Google Scholar 

  57. Hecht, E. Optics 4th edn (Addison Wesley, 2002).

    Google Scholar 

Download references

Acknowledgements

We acknowledge fruitful discussions with T. Cocker, R. Huber, C. Ropers, R. Wolkow, J. Burgess and D. Jenson. This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canada Foundation for Innovation (CFI), the Alberta Science and Research Investments Program (ASRIP), the Alberta Innovates Technology Futures (AITF) Strategic Chairs Program, and the Informatics Circle of Research Excellence (iCORE) Centre for Interdisciplinary Nanoscience (iCiNano). V.J. acknowledges support from NSERC and AITF. K.I. acknowledges support from the Danish Council for Independent Research under Postdoc Project 64092. C.R. acknowledges support from the German Academic Exchange Service (DAAD). We thank R. Wolkow for providing the Si sample, S. Xu (Alberta Centre for Surface Engineering and Science, University of Alberta) for scanning electron microscope imaging of the tungsten tip and A. He for secondary ion mass spectrometry of the Si sample. We are grateful for technical support from G. Popowich, D. Fortin and B. Shi. Electromagnetic simulations were carried out using COMSOL Multiphysics with licence provided by CMC Microsystems.

Author information

Authors and Affiliations

  1. Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada

    Vedran Jelic, Peter H. Nguyen, Graham J. Hornig, Haille M. Sharum, James R. Hoffman, Mark R. Freeman & Frank A. Hegmann

  2. DTU Fotonik – Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark

    Krzysztof Iwaszczuk

  3. 4th Physical Institute, University of Göttingen, 37077 Göttingen, Germany

    Christopher Rathje

Authors
  1. Vedran Jelic
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Krzysztof Iwaszczuk
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Peter H. Nguyen
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Christopher Rathje
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Graham J. Hornig
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Haille M. Sharum
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. James R. Hoffman
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Mark R. Freeman
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Frank A. Hegmann
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

V.J. and F.A.H. conceived the UHV THz-STM experiment, interpreted the data and designed the set-up. V.J. and J.R.H. built the set-up. V.J. carried out experiments, analysed the data and wrote the manuscript. V.J. and K.I. developed the Bardeen tunnelling model, hot electron model and fits to the data. P.H.N., C.R. and G.J.H. performed the electromagnetic simulations. P.H.N., G.J.H., H.M.S. and J.R.H. contributed to preliminary measurements with the UHV THz-STM system. M.R.F. contributed to interpretation of the data. F.A.H. initiated and supervised the project. All authors contributed to discussions.

Corresponding authors

Correspondence to Vedran Jelic or Frank A. Hegmann.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 2420 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Jelic, V., Iwaszczuk, K., Nguyen, P. et al. Ultrafast terahertz control of extreme tunnel currents through single atoms on a silicon surface. Nature Phys 13, 591–598 (2017). https://doi.org/10.1038/nphys4047

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphys4047

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing