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.

  • Letter
  • Published:

Coherent commensurate electronic states at the interface between misoriented graphene layers

Abstract

Graphene and layered materials in general exhibit rich physics and application potential owing to their exceptional electronic properties, which arise from the intricate π-orbital coupling and the symmetry breaking in twisted bilayer systems1,2,3,4,5,6,7,8,9,10,11,12,13,14. Here, we report room-temperature experiments to study electrical transport across a bilayer graphene interface with a well-defined rotation angle between the layers that is controllable in situ. This twisted interface is artificially created in mesoscopic pillars made of highly oriented pyrolytic graphite by mechanical actuation. The overall measured angular dependence of the conductivity is consistent with a phonon-assisted transport mechanism that preserves the electron momentum of conduction electrons passing the interface15. The most intriguing observations are sharp conductivity peaks at interlayer rotation angles of 21.8° and 38.2°. These angles correspond to a commensurate crystalline superstructure leading to a coherent two-dimensional (2D) electronic interface state. Such states, predicted by theory16,17, form the basis for a new class of 2D weakly coupled bilayer systems with hitherto unexplored properties and applications.

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

Access options

Buy this article

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

Figure 1: Experimental procedure.
Figure 2: Interlayer conductivity.
Figure 3: Commensurate twisted configurations.
Figure 4: Momentum-space representation of bilayer graphene coupling at commensurate twist angles θ = 21.8° and 38.2°.

Similar content being viewed by others

References

  1. Geim, A. K. Graphene: status and prospects. Science 324, 1530–1534 (2009).

    Article  CAS  Google Scholar 

  2. Ponomarenko, L. A. et al. Cloning of dirac fermions in graphene superlattices. Nature 497, 594–597 (2013).

    Article  CAS  Google Scholar 

  3. Yankowitz, M. et al. Emergence of superlattice Dirac points in graphene on hexagonal boron nitride. Nature Phys. 8, 382–386 (2012).

    Article  CAS  Google Scholar 

  4. Dean, C. R. et al. Hofstadter's butterfly and the fractal quantum hall effect in moiré superlattices. Nature 497, 598–602 (2013).

    Article  CAS  Google Scholar 

  5. Hunt, B. et al. Massive Dirac fermions and Hofstadter butterfly in a van der Waals heterostructure. Science 340, 1427–1430 (2013).

    Article  CAS  Google Scholar 

  6. Schmidt, H., Rode, J. C., Smirnov, D. & Haug, R. J. Superlattice structures in twisted bilayers of folded graphene. Nature Commun. 5, 5742 (2014).

    Article  Google Scholar 

  7. Li, G. et al. Observation of Van Hove singularities in twisted graphene layers. Nature Phys. 6, 109–113 (2009).

    Article  Google Scholar 

  8. Kim, K. S. et al. Coexisting massive and massless Dirac fermions in symmetry-broken bilayer graphene. Nature Mater. 12, 887–892 (2013).

    Article  CAS  Google Scholar 

  9. Trambly de Laissardière, G., Mayou, D. & Magaud, L. Localization of Dirac electrons in rotated graphene bilayers. Nano Lett. 10, 804–808 (2010).

    Article  Google Scholar 

  10. Lee, D. S. et al. Quantum hall effect in twisted bilayer graphene. Phys. Rev. Lett. 107, 216602 (2011).

    Article  Google Scholar 

  11. Hass, J. et al. Why multilayer graphene on 4 H − SiC (0001) behaves like a single sheet of graphene. Phys. Rev. Lett. 100, 125504 (2008).

    Article  CAS  Google Scholar 

  12. Luican, A. et al. Single-layer behavior and its breakdown in twisted graphene layers. Phys. Rev. Lett. 106, 126802 (2011).

    Article  CAS  Google Scholar 

  13. Lopes dos Santos, J. M. B., Peres, N. M. R. & Castro Neto, A. H. Graphene bilayer with a twist: electronic structure. Phys. Rev. Lett. 99, 256802 (2007).

    Article  CAS  Google Scholar 

  14. Shallcross, S., Sharma, S., Kandelaki, E. & Pankratov, O. A. Electronic structure of turbostratic graphene. Phys. Rev. B 81, 165105 (2010).

    Article  Google Scholar 

  15. Perebeinos, V., Tersoff, J. & Avouris, P. Phonon-mediated interlayer conductance in twisted graphene bilayers. Phys. Rev. Lett. 109, 236604 (2012).

    Article  CAS  Google Scholar 

  16. Shallcross, S., Sharma, S. & Pankratov, O. A. Quantum interference at the twist boundary in graphene. Phys. Rev. Lett. 101, 056803 (2008).

    Article  CAS  Google Scholar 

  17. Mele, E. J. Commensuration and interlayer coherence in twisted bilayer graphene. Phys. Rev. B 81, 161405 (2010).

    Article  Google Scholar 

  18. Bistritzer, R. & MacDonald, A. H. Transport between twisted graphene layers. Phys. Rev. B 81, 245412 (2010).

    Article  Google Scholar 

  19. Koren, E., Lörtscher, E., Rawlings, C., Knoll, A. W. & Duerig, U. Adhesion and friction in mesoscopic graphite contacts. Science 348, 679–683 (2015).

    Article  CAS  Google Scholar 

  20. Koren, E., Knoll, A. W., Lörtscher, E. & Duerig, U. Direct experimental observation of stacking fault scattering in highly oriented pyrolytic graphite meso-structures. Nature Commun. 5, 5837 (2014).

    Article  CAS  Google Scholar 

  21. Kim, Y. et al. Breakdown of the interlayer coherence in twisted bilayer graphene. Phys. Rev. Lett. 110, 096602 (2013).

    Article  Google Scholar 

  22. Datta, S. Quantum Transport: Atom to Transistor (Cambridge Univ. Press, 2005).

    Book  Google Scholar 

  23. Habib, K. M. M., Sylvia, S. S., Ge, S., Neupane, M. & Lake, R. K. The coherent interlayer resistance of a single, rotated interface between two stacks of AB graphite. Appl. Phys. Lett. 103, 243114 (2013).

    Article  Google Scholar 

Download references

Acknowledgements

We thank U. Drechsler and M. Tschudy for invaluable technical support and J. Tersoff, V. Perebeinos, N. Moll and R. Allenspach for stimulating discussions. The work was supported by the FP7 Marie Curie Actions of the European Commission, ITN fellowship cQOM (Project ID 290161) and by the Swiss National Science Foundation, Ambizione Grant No. PZ00P2 161388 (E.K.). Work at TAU was supported by the Israel Science Foundation under grant No. 1740/13, the Lise-Meitner Minerva Center for Computational Quantum Chemistry, and the Center for Nanoscience and Nanotechnology at Tel-Aviv University.

Author information

Authors and Affiliations

Authors

Contributions

E.K., A.K. and U.D. jointly conceived the experimental concept. E.K. performed the experimental work including reactive ion etching, AFM characterization, electrical transport measurements and data analysis. E.K. also participated in the writing of the manuscript. A.K. provided operational guidance for the AFM. E.L. was responsible for the electron beam lithography and metal lift-off process for the fabrication of the metal masks. U.D. was responsible for the writing of the manuscript. I.L. participated in the development of the global (GRI) and local (LRI) registry index concept and implemented them within a computational code. I.L. also performed the numerical calculations of the GRI, LRI and interlayer transport and participated in the writing of the manuscript. O.H. conceived the concept of the GRI and LRI, developed and implemented the interlayer transport code and participated in the writing of the manuscript.

Corresponding authors

Correspondence to Elad Koren or Urs Duerig.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 2006 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Koren, E., Leven, I., Lörtscher, E. et al. Coherent commensurate electronic states at the interface between misoriented graphene layers. Nature Nanotech 11, 752–757 (2016). https://doi.org/10.1038/nnano.2016.85

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2016.85

This article is cited by

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