Letter | Published:

Tracking the ultrafast motion of a single molecule by femtosecond orbital imaging

Nature volume 539, pages 263267 (10 November 2016) | Download Citation

Abstract

Watching a single molecule move on its intrinsic timescale has been one of the central goals of modern nanoscience, and calls for measurements that combine ultrafast temporal resolution1,2,3,4,5,6,7,8 with atomic spatial resolution9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30. Steady-state experiments access the requisite spatial scales, as illustrated by direct imaging of individual molecular orbitals using scanning tunnelling microscopy9,10,11 or the acquisition of tip-enhanced Raman and luminescence spectra with sub-molecular resolution26,27,28. But tracking the intrinsic dynamics of a single molecule directly in the time domain faces the challenge that interactions with the molecule must be confined to a femtosecond time window. For individual nanoparticles, such ultrafast temporal confinement has been demonstrated18 by combining scanning tunnelling microscopy with so-called lightwave electronics1,2,3,4,5,6,7,8, which uses the oscillating carrier wave of tailored light pulses to directly manipulate electronic motion on timescales faster even than a single cycle of light. Here we build on ultrafast terahertz scanning tunnelling microscopy to access a state-selective tunnelling regime, where the peak of a terahertz electric-field waveform transiently opens an otherwise forbidden tunnelling channel through a single molecular state. It thereby removes a single electron from an individual pentacene molecule’s highest occupied molecular orbital within a time window shorter than one oscillation cycle of the terahertz wave. We exploit this effect to record approximately 100-femtosecond snapshot images of the orbital structure with sub-ångström spatial resolution, and to reveal, through pump/probe measurements, coherent molecular vibrations at terahertz frequencies directly in the time domain. We anticipate that the combination of lightwave electronics1,2,3,4,5,6,7,8 and the atomic resolution of our approach will open the door to visualizing ultrafast photochemistry and the operation of molecular electronics on the single-orbital scale.

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References

  1. 1.

    et al. Tomographic imaging of molecular orbitals. Nature 432, 867–871 (2004)

  2. 2.

    et al. Attosecond control and measurement: lightwave electronics. Science 317, 769–775 (2007)

  3. 3.

    et al. Direct observation of electron propagation and dielectric screening on the atomic length scale. Nature 517, 342–346 (2015)

  4. 4.

    et al. Real-time observation of interfering crystal electrons in high-harmonic generation. Nature 523, 572–575 (2015)

  5. 5.

    et al. Quantum coherent optical phase modulation in an ultrafast transmission electron microscope. Nature 521, 200–203 (2015)

  6. 6.

    , & Attosecond control of electrons emitted from a nanoscale metal tip. Nature 475, 78–81 (2011)

  7. 7.

    et al. Terahertz control of nanotip photoemission. Nature Phys. 10, 432–436 (2014)

  8. 8.

    , , & Nitrogen plasma formation through terahertz-induced ultrafast electron field emission. Optica 2, 116–123 (2015)

  9. 9.

    , , , & Molecules on insulating films: scanning-tunneling microscopy imaging of individual molecular orbitals. Phys. Rev. Lett. 94, 026803 (2005)

  10. 10.

    & Controlling the dynamics of a single atom in lateral atom manipulation. Science 306, 242–247 (2004)

  11. 11.

    , & Single-molecule vibrational spectroscopy and microscopy. Science 280, 1732–1735 (1998)

  12. 12.

    & Ultrafast time resolution in scanned probe microscopies. Appl. Phys. Lett. 57, 2031 (1990)

  13. 13.

    & Picosecond resolution in scanning tunneling microscopy. Science 262, 1029–1032 (1993)

  14. 14.

    , , & Radio-frequency scanning tunnelling microscopy. Nature 450, 85–88 (2007)

  15. 15.

    , , & Real-space imaging of transient carrier dynamics by nanoscale pump-probe microscopy. Nature Photon. 4, 869–874 (2010)

  16. 16.

    , , , & Measurement of fast electron spin relaxation times with atomic resolution. Science. 329, 1628–1630 (2010)

  17. 17.

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

  18. 18.

    et al. An ultrafast terahertz scanning tunnelling microscope. Nature Photon. 7, 620–625 (2013)

  19. 19.

    et al. Probing ultrafast spin dynamics with optical pump-probe scanning tunnelling microscopy. Nature Nanotech. 9, 588–593 (2014)

  20. 20.

    , , , & Exciton dynamics of C60-based single-photon emitters explored by Hanbury Brown-Twiss scanning tunnelling microscopy. Nature Commun. 6, 8461 (2015)

  21. 21.

    et al. Ultrafast and nanoscale plasmonic phenomena in exfoliated graphene revealed by infrared pump-probe nanoscopy. Nano Lett. 14, 894–900 (2014)

  22. 22.

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

  23. 23.

    et al. Mapping molecular motions leading to charge delocalization with ultrabright electrons. Nature 496, 343–346 (2013)

  24. 24.

    Four-dimensional electron microscopy. Science 328, 187–193 (2010)

  25. 25.

    et al. Ultrafast pump-probe force microscopy with nanoscale resolution. Appl. Phys. Lett. 106, 083113 (2015)

  26. 26.

    et al. Chemical mapping of a single molecule by plasmon-enhanced Raman scattering. Nature 498, 82–86 (2013)

  27. 27.

    et al. Vibronic motion with joint angstrom–femtosecond resolution observed through Fano progressions recorded within one molecule. ACS Nano 8, 54–63 (2014)

  28. 28.

    et al. Visualizing coherent intermolecular dipole–dipole coupling in real space. Nature 531, 623–627 (2016)

  29. 29.

    et al. Nanomechanical oscillations in a single-C60 transistor. Nature 407, 57–60 (2000)

  30. 30.

    , & Terahertz field enhancement and photon-assisted tunneling in single-molecule transistors. Phys. Rev. Lett. 115, 138302 (2015)

  31. 31.

    A simple low-temperature ultrahigh-vacuum scanning tunneling microscope capable of atomic manipulation. Rev. Sci. Instrum. 67, 2960–2965 (1996)

  32. 32.

    , & Local thickness determination of thin insulator films via localized states. Appl. Phys. Lett. 104, 231606 (2014)

  33. 33.

    Introduction to Scanning Tunneling Microscopy (Oxford Univ. Press, 1993)

  34. 34.

    , , , & Electronic structure calculations on workstation computers: the program system TURBOMOLE. Chem. Phys. Lett. 162, 165–169 (1989)

  35. 35.

    & External vibrations of hydrocarbons on Cu(100). J. Chem. Phys. 103, 5860–5863 (1995)

  36. 36.

    et al. Damping of molecular motion on a solid substrate: evidence for electron-hole pair creation. Phys. Rev. Lett. 80, 121–124 (1998)

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Acknowledgements

We thank A. Pöllmann, F. Albrecht, R. Kronfeldner, M. Eisele and M. Furthmeier for assistance, and F. Evers, F. A. Hegmann, V. Jelic, P. C. M. Planken, M. Grifoni and K. Richter for discussions. We acknowledge financial support from the Volkswagen Foundation (Lichtenberg program), the European Research Council through grant number 305003 (QUANTUMsubCYCLE), and the Deutsche Forschungsgemeinschaft (DFG) through GRK 1570 and research grants HU1598/3 and CO1492/1. T.L.C. thanks the A. v. Humboldt Foundation.

Author information

Author notes

    • Tyler L. Cocker
    •  & Dominik Peller

    These authors contributed equally to this work.

Affiliations

  1. Department of Physics, University of Regensburg, 93040 Regensburg, Germany

    • Tyler L. Cocker
    • , Dominik Peller
    • , Ping Yu
    • , Jascha Repp
    •  & Rupert Huber

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Contributions

T.L.C., D.P., P.Y., J.R. and R.H. conceived, set up and carried out the experiments. T.L.C., D.P., J.R. and R.H. analysed the data and wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Jascha Repp or Rupert Huber.

Reviewer Information

Nature thanks H. Shigekawa and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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DOI

https://doi.org/10.1038/nature19816

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