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Isotope-induced partial localization of core electrons in the homonuclear molecule N2

Nature volume 437, pages 711–715 (2005)Cite this article

Abstract

Because of inversion symmetry and particle exchange, all constituents of homonuclear diatomic molecules are in a quantum mechanically non-local coherent state; this includes the nuclei and deep-lying core electrons. Hence, the molecular photoemission can be regarded as a natural double-slit experiment1: coherent electron emission originates from two identical sites, and should give rise to characteristic interference patterns2. However, the quantum coherence is obscured if the two possible symmetry states of the electronic wavefunction (‘gerade’ and ‘ungerade’) are degenerate; the sum of the two exactly resembles the distinguishable, incoherent emission from two localized core sites. Here we observe the coherence of core electrons in N2 through a direct measurement of the interference exhibited in their emission. We also explore the gradual transition to a symmetry-broken system of localized electrons by comparing different isotope-substituted species—a phenomenon analogous to the acquisition of partial ‘which-way’ information in macroscopic double-slit experiments3.

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Figure 1: Experimental set-up for a photoelectron-fragment ion coincidence experiment at a synchrotron radiation source.
Figure 2: Symmetry resolved photoelectron distributions in the molecule frame.
Figure 3: Photoelectron angular distribution parameter β for N 2 :N(1 s ) electron emission in the photon-energy range 410–450 eV.
Figure 4: Isotope effect on N2.

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References

  1. Lindner, F. et al. Attosecond double-slit experiment. Phys. Rev. Lett. 95, 040401 (2005)

    Article  ADS  CAS  Google Scholar 

  2. Briggs, J. S. & Walter, M. Oscillatory structure of molecular photoionisation cross-sections. Phys. Essays 13, 297–302 (2000)

    Article  ADS  CAS  Google Scholar 

  3. Hackermüller, L., Hornberger, K., Brezger, B., Zeilinger, A. & Arndt, M. Decoherence of matter waves by thermal emission of radiation. Nature 427, 711–714 (2004)

    Article  ADS  Google Scholar 

  4. Mulliken, R. S. Band spectra and atomic nuclei. Trans. Faraday Soc. 25, 634–645 (1929)

    Article  CAS  Google Scholar 

  5. Herzberg, G. Molecular Spectra and Molecular Structure, Spectra of Diatomic Molecules Vol. 1, 139 (Krieger, Malabar, Florida, 1989)

    Google Scholar 

  6. Pique, J. P., Hartmann, F., Bacis, R., Churassy, S. & Koffend, J. B. Hyperfine-induced ungerade-gerade symmetry breaking in a homonuclear diatomic molecule near a dissociation limit: 127I2 at the 2P3/2-2P3/2 limit. Phys. Rev. Lett. 52, 267–270 (1984)

    Article  ADS  CAS  Google Scholar 

  7. Critchley, A. D. J., Hughes, A. N. & McNab, I. R. Direct measurement of a pure rotation transition in H2 . Phys. Rev. Lett. 86, 1725–1728 (2001)

    Article  ADS  CAS  Google Scholar 

  8. Cacciani, P. & Kokoouline, V. Predissociation induced by ungerade-gerade symmetry breaking in 6Li7Li molecule. Phys. Rev. Lett. 84, 5296–5299 (2000)

    Article  ADS  CAS  Google Scholar 

  9. Bouloufa, N. et al. Predissociation induced by ungerade-gerade symmetry breaking in the B1Πu state of the 6Li7Li molecule. Phys. Rev. A. 63, 042507 (2001)

    Article  ADS  Google Scholar 

  10. Siegbahn, K., et al. ESCA—Atomic, Molecular and Solid State Structure Studied by Means of Electron Spectroscopy (Almqvist & Wiksells, Uppsala, 1967)

    Google Scholar 

  11. Broer, R. & Nieuwpoort, W. C. Hole localization and symmetry breaking. J. Mol. Struct. 458, 19–25 (1999)

    Article  CAS  Google Scholar 

  12. Heiser, F. et al. Demonstration of strong forward-backward asymmetry in the C1s photoelectron angular distribution from oriented CO molecules. Phys. Rev. Lett. 79, 2435–2437 (1997)

    Article  ADS  CAS  Google Scholar 

  13. Becker, U. Angle-resolved electron–electron and electron–ion coincidence spectroscopy: new tools for photoionization studies. J. Electron. Spectrosc. Relat. Phenom. 112, 47–65 (2000)

    Article  CAS  Google Scholar 

  14. Hergenhahn, U., Kugeler, O., Rüdel, A., Rennie, E. E. & Bradshaw, A. M. Symmetry-selective observation of the N 1s shape resonance in N2 . J. Phys. Chem. A 105, 5704–5708 (2001)

    Article  CAS  Google Scholar 

  15. Shigemasa, E. et al. Angular distributions of 1sσ photoelectrons from fixed-in-space N2 molecules. Phys. Rev. Lett. 74, 359–362 (1995)

    Article  ADS  CAS  Google Scholar 

  16. Pavlychev, A. A. et al. Dynamic properties of N and O 1s-1σu* shape resonances in N2 and CO2 molecules. Phys. Rev. Lett. 81, 3623–3626 (1998)

    Article  ADS  CAS  Google Scholar 

  17. Cherepkov, N. A. et al. Manifestation of many-electron correlations in photoionization of the K shell of N2 . Phys. Rev. Lett. 84, 250–253 (2000)

    Article  ADS  CAS  Google Scholar 

  18. Jahnke, T. et al. Circular dichroism in K-shell ionization from fixed-in-space CO and N2 molecules. Phys. Rev. Lett. 88, 073002 (2002)

    Article  ADS  CAS  Google Scholar 

  19. Weber, Th. et al. K-shell photoionization of CO and N2: is there a link between the photoelectron angular distribution and the molecular decay dynamics? J. Phys. B 34, 3669–3678 (2001)

    Article  ADS  CAS  Google Scholar 

  20. Yang, C. N. On the angular distribution in nuclear reactions and coincidence measurements. Phys. Rev. 74, 764–772 (1948)

    Article  ADS  CAS  Google Scholar 

  21. Dehmer, J. L. & Dill, D. Shape resonances in K-shell photoionization of diatomic molecules. Phys. Rev. Lett. 35, 213–215 (1975)

    Article  ADS  CAS  Google Scholar 

  22. Skytt, P. et al. Quenching of symmetry breaking in resonant inelastic X-ray scattering by detuned excitation. Phys. Rev. Lett. 77, 5035–5038 (1996)

    Article  ADS  CAS  Google Scholar 

  23. Golovin, A. V. et al. Observation of site-specific electron emission in the decay of superexcited O2 . Phys. Rev. Lett. 79, 4554–4557 (1997)

    Article  ADS  CAS  Google Scholar 

  24. Björneholm, O. et al. Doppler splitting of in-flight auger decay of dissociating oxygen molecules: the localization of delocalized core holes. Phys. Rev. Lett. 84, 2826–2829 (2000)

    Article  ADS  Google Scholar 

  25. Kosugi, N. Spin-orbit and exchange interactions in molecular inner shell spectroscopy. J. Electron. Spectrosc. Relat. Phenom. 137–140, 335–343 (2004)

    Article  Google Scholar 

  26. Greiner, M., Mandel, O., Esslinger, T., Hänsch, T. W. & Bloch, I. Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms. Nature 415, 39–44 (2002)

    Article  ADS  CAS  Google Scholar 

  27. Domcke, W. & Cederbaum, L. S. Vibronic coupling and symmetry breaking in core electron ionization. Chem. Phys. 25, 189–196 (1977)

    Article  CAS  Google Scholar 

  28. Bayer, M. et al. Coupling and entangling of quantum states in quantum dot molecules. Science 291, 451–453 (2001)

    Article  ADS  CAS  Google Scholar 

  29. Hayashi, T., Fujisawa, T., Cheong, H. D., Jeong, Y. H. & Hirayama, Y. Coherent manipulation of electronic states in a double quantum dot. Phys. Rev. Lett. 91, 226804 (2003)

    Article  ADS  CAS  Google Scholar 

  30. Wabnitz, H. et al. Multiple ionization of atom clusters by intense soft X-rays from a free-electron laser. Nature 420, 482–485 (2002)

    Article  ADS  CAS  Google Scholar 

  31. Zimmermann, B., Wang, K. & McKoy, V. Circular dichroism in K-shell ionization from fixed-in-space CO and N2 . Phys. Rev. A. 67, 042711 (2003)

    Article  ADS  Google Scholar 

  32. Stener, M., Fronzoni, G. & Decleva, P. Time dependent density functional study of the symmetry resolved N 1s photoionization in N2 . Chem. Phys. Lett. 351, 469–474 (2002)

    Article  ADS  CAS  Google Scholar 

  33. Semenov, S. K. & Cherepkov, N. A. Generalization of atomic random-phase-approximation method for diatomic molecules. II. N2 K-shell photoionization. Phys. Rev. A. 66, 022708 (2002)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank J. Bozek, R. Diéz Muiño, F. J. García de Abajo, C. S. Fadley and M. A. Van Hove for many discussions about core–hole delocalization and coherent photoelectron emission in homonuclear molecules. The assistance of R. Püttner and F. Gelmukhanov in the interpretation of the effect of isotope substitution on the vibrational structure and the Franck–Condon factors is also acknowledged. The work was partly supported by the Bundesministerium für Bildung und Forschung (BMBF) and the Alexander von Humboldt Foundation (B.Z.).

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Author notes

  1. Slobodan Cvejanović & Burkhard Langer

    Present address: Medical Faculty, Physics Department, University of Rijeka, 51000, Rijeka, Croatia

  2. Oliver Geßner

    Present address: Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada

  3. Toralf Lischke & Georg Prümper

    Present address: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, 980-8577, Japan

  4. Björn Zimmermann

    Present address: Max-Planck-Institut für Physik komplexer Systeme, 01187, Dresden, Germany

Authors and Affiliations

  1. Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195, Berlin, Germany

    Daniel Rolles, Markus Braune, Slobodan Cvejanović, Oliver Geßner, Rainer Hentges, Sanja Korica, Toralf Lischke, Georg Prümper, Axel Reinköster, Jens Viefhaus & Uwe Becker

  2. Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489, Berlin, Germany

    Burkhard Langer

  3. California Institute of Technology, Pasadena, California, 91125, USA

    Björn Zimmermann & Vincent McKoy

  4. Institut für Physikalische Chemie, Universität Würzburg, Würzburg, 97074, Germany

    Burkhard Langer

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Correspondence to Uwe Becker.

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Rolles, D., Braune, M., Cvejanović, S. et al. Isotope-induced partial localization of core electrons in the homonuclear molecule N2. Nature 437, 711–715 (2005). https://doi.org/10.1038/nature04040

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