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:

Symmetry breaking in twisted double bilayer graphene

Nature Physics volume 17, pages 26–30 (2021)Cite this article

Subjects

Abstract

The flat bands that appear in some twisted van der Waals heterostructures provide a setting in which strong interactions between electrons lead to a variety of correlated phases1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20. In particular, heterostructures of twisted double bilayer graphene host correlated insulating states that can be tuned by both the twist angle and an external electric field11,12,13,14. Here, we report electrical transport measurements of twisted double bilayer graphene with which we examine the fundamental role of spontaneous symmetry breaking in its phase diagram. The metallic states near each of the correlated insulators exhibit abrupt drops in their resistivity as the temperature is lowered, along with associated nonlinear current–voltage characteristics. Despite qualitative similarities to superconductivity, the simultaneous reversals in the sign of the Hall coefficient point instead to spontaneous symmetry breaking as the origin of the abrupt resistivity drops, whereas Joule heating seems to underlie the nonlinear transport. Our results suggest that similar mechanisms are probably relevant across a broader class of semiconducting flat band van der Waals heterostructures.

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

Fig. 1: Tunable band structure and transport in a 1.30∘ tDBG device.
Fig. 2: Temperature-dependent transport and Joule heating in tDBG.
Fig. 3: Evidence for spontaneous symmetry breaking inside the halo region.

Similar content being viewed by others

Data availability

Source data are available for this paper. All other data that support the plots within this paper and other findings of this study are available from the corresponding authors on reasonable request.

References

  1. Cao, Y. et al. Correlated insulator behaviour at half-filling in magic-angle graphene superlattices. Nature 556, 80–84 (2018).

    Article  ADS  Google Scholar 

  2. Cao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).

    Article  ADS  Google Scholar 

  3. Yankowitz, M. et al. Tuning superconductivity in twisted bilayer graphene. Science 363, 1059–1064 (2019).

    Article  ADS  Google Scholar 

  4. Sharpe, A. L. et al. Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene. Science 365, 605–608 (2019).

    Article  ADS  Google Scholar 

  5. Cao, Y. et al. Strange metal in magic-angle graphene with near Planckian dissipation. Phys. Rev. Lett. 124, 076801 (2020).

    Article  ADS  Google Scholar 

  6. Polshyn, H. et al. Large linear-in-temperature resistivity in twisted bilayer graphene. Nat. Phys. 15, 1011–1016 (2019).

    Article  Google Scholar 

  7. Lu, X. et al. Superconductors, orbital magnets, and correlated states in magic angle bilayer graphene. Nature 574, 653–657 (2019).

    Article  ADS  Google Scholar 

  8. Serlin, M. et al. Intrinsic quantized anomalous Hall effect in a moiré heterostructure. Science 367, 900–903 (2020).

    Article  ADS  Google Scholar 

  9. Stepanov, P. et al. Untying the insulating and superconducting orders in magic-angle graphene. Nature 583, 375–378 (2020).

    Article  ADS  Google Scholar 

  10. Saito, Y., Ge, J., Watanabe, K., Tanighuchi, T. & Young, A. F. Independent superconductors and correlated insulators in twisted bilayer graphene. Nat. Phys. https://doi.org/10.1038/s41567-020-0928-3 (2020).

  11. Shen, C. et al. Correlated states in twisted double bilayer graphene. Nat. Phys. 16, 520–525 (2020).

    Article  Google Scholar 

  12. Liu, X. et al. Tunable spin-polarized correlated states in twisted double bilayer graphene. Nature 583, 221–225 (2020).

    Article  ADS  Google Scholar 

  13. Cao, Y. et al. Tunable correlated states and spin-polarized phases in twisted bilayer-bilayer graphene. Nature 583, 215–220 (2020).

    Article  ADS  Google Scholar 

  14. Burg, G. W. et al. Correlated insulating states in twisted double bilayer graphene. Phys. Rev. Lett. 123, 197702 (2019).

    Article  ADS  Google Scholar 

  15. Chen, G. et al. Evidence of a gate-tunable Mott insulator in a trilayer graphene moiré superlattice. Nat. Phys. 15, 237–241 (2019).

    Article  Google Scholar 

  16. Chen, G. et al. Signatures of tunable superconductivity in a trilayer graphene moiré superlattice. Nature 572, 215–219 (2019).

    Article  Google Scholar 

  17. Chen, G. et al. Tunable correlated Chern insulator and ferromagnetism in a moiré superlattice. Nature 579, 56–61 (2020).

    Article  ADS  Google Scholar 

  18. Tang, Y. et al. Simulation of Hubbard model physics in WSe2/WS2 moiré superlattices. Nature 579, 353–358 (2020).

    Article  ADS  Google Scholar 

  19. Regan, E. C. et al. Mott and generalized wigner crystal states in WSe2/WS2 moiré superlattices. Nature 579, 359–363 (2020).

    Article  ADS  Google Scholar 

  20. Wang, L. et al. Correlated electronic phases in twisted bilayer transistion metal dichalcogenides. Nat. Mater. 19, 861–866 (2020).

    Article  Google Scholar 

  21. Po, H. C., Zou, L., Vishwanath, A. & Senthil, T. Origin of Mott insulating behavior and superconductivity in twisted bilayer graphene. Phys. Rev. X 8, 031089 (2018).

    Google Scholar 

  22. Bistritzer, R. & MacDonald, A. H. Moiré bands in twisted double-layer graphene. Proc. Natl Acad. Sci. USA 108, 12233–12237 (2011).

    Article  ADS  Google Scholar 

  23. Jiang, Y. et al. Charge order and broken rotational symmetry in magic-angle twisted bilayer graphene. Nature 573, 91–95 (2019).

    Article  ADS  Google Scholar 

  24. Kerelsky, A. et al. Maximized electron interactions at the magic angle in twisted bilayer graphene. Nature 572, 95–100 (2019).

    Article  ADS  Google Scholar 

  25. Xie, Y. et al. Spectroscopic signatures of many-body correlations in magic-angle twisted bilayer graphene. Nature 572, 101–105 (2019).

    Article  ADS  Google Scholar 

  26. Choi, Y. et al. Electronic correlations in twisted bilayer graphene near the magic angle. Nat. Phys. 15, 1174–1180 (2019).

    Article  Google Scholar 

  27. Adak, P. C. et al. Tunable bandwidths and gaps in twisted double bilayer graphene on the verge of correlations. Phys. Rev. B 101, 125428 (2020).

    Article  ADS  Google Scholar 

  28. Lee, J. Y. et al. Theory of correlated insulating behaviour and spin-triplet superconductivity in twisted double bilayer graphene. Nat. Commun. 10, 5333 (2019).

    Article  ADS  Google Scholar 

  29. Chen, J.-H., Jang, C., Xiao, S., Ishigami, M. & Fuhrer, M. S. Intrinsic and extrinsic performance limits of graphene devices on SiO2. Nat. Nanotechnol. 3, 206–209 (2008).

    Article  Google Scholar 

  30. Dean, C. R. et al. Boron nitride substrates for high-quality graphene electronics. Nat. Nanotechnol. 5, 722–726 (2010).

    Article  ADS  Google Scholar 

  31. Kasuya, T. Electrical resistance of ferromagnetic metals. Prog. Theor. Phys. 16, 58–63 (1956).

    Article  ADS  Google Scholar 

  32. Petrova, A. E., Bauer, E. D., Krasnorussky, V. & Stishov, S. M. Behavior of the electrical resistivity of MnSi at the ferromagnetic phase transition. Phys. Rev. B 74, 092401 (2006).

    Article  ADS  Google Scholar 

  33. Rotter, M. et al. Spin-density-wave anomaly at 140 K in the ternary iron arsenide BaFe2As2. Phys. Rev. B 78, 020503(R) (2008).

    Article  ADS  Google Scholar 

  34. Kim, K. et al. van der Waals heterostructures with high accuracy rotational alignment. Nano Lett. 16, 1989–1995 (2016).

    Article  ADS  Google Scholar 

  35. Cao, Y. et al. Superlattice-induced insulating states and valley-protected orbits in twisted bilayer graphene. Phys. Rev. Lett. 117, 116804 (2016).

    Article  ADS  Google Scholar 

  36. Wang, L. et al. One-dimensional electrical contact to a two-dimensional material. Science 342, 614–617 (2013).

    Article  ADS  Google Scholar 

  37. Wong, D. et al. Cascade of electronic transitions in magic-angle twisted bilayer graphene. Nature 582, 198–202 (2020).

    Article  ADS  Google Scholar 

  38. Zondiner, U. et al. Cascade of phase transitions and Dirac revivals in magic-angle graphene. Nature 582, 203–208 (2020).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank C. Dean, A. Young, J.-H. Chu, D. Cobden, S. Chen, X. Liu, P. Kim, B. Lian, A. MacDonald, L. Levitov and L. Fu for helpful discussions. Technical support for the dilution refrigerator was provided by A. Manna and Z. Fei. This work was primarily supported by NSF MRSEC grant no. 1719797. M.Y. acknowledges partial support from the Army Research Office under grant no. W911NF-20-1-0211. The theoretical calculation was partially supported by DOE BES grant no. DE-SC0018171. X.X. acknowledges support from the Boeing Distinguished Professorship in Physics. X.X. and M.Y. acknowledge support from the State of Washington funded Clean Energy Institute. This work made use of a dilution refrigerator system that was provided by NSF grant no. DMR-1725221. Y. Li acknowledges the support of the China Scholarship Council. K.W. and T.T. were supported by the Elemental Strategy Initiative conducted by the MEXT, Japan, and the CREST (JPMJCR15F3), JST.

Author information

Authors and Affiliations

  1. Department of Physics, University of Washington, Seattle, WA, USA

    Minhao He, Yuhao Li, Jiaqi Cai, Yang Liu, Xiaodong Xu & Matthew Yankowitz

  2. National Institute for Materials Science, Tsukuba, Japan

    K. Watanabe & T. Taniguchi

  3. Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA

    Xiaodong Xu & Matthew Yankowitz

Authors
  1. Minhao He
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yuhao Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jiaqi Cai
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yang Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. K. Watanabe
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. T. Taniguchi
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Xiaodong Xu
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Matthew Yankowitz
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

M.Y., X.X. and M.H. conceived the experiment. M.H. and Y. Li fabricated the devices, assisted by Y. Liu. M.H. performed the measurements, with assistance from Y. Li and Y. Liu. J.C. performed band structure calculation. K.W. and T.T. provided the bulk BN crystals. M.H., X.X. and M.Y. analysed the data and wrote the paper with input from all authors.

Corresponding authors

Correspondence to Xiaodong Xu or Matthew Yankowitz.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Optical microscope images of the five tDBG devices.

The twist angle of each device is denoted at the top left corner of each image. All scale bars are 10 μm.

Extended Data Fig. 2 Transport in tDBG at a variety of twist angles.

a-e, ρ as a function of n and D in all five devices acquired at B = 0 T. All are acquired at T = 2 K, except for c which is acquired at T = 20 mK. f-j, Corresponding RH for the same devices. The maps in f, h and i are antisymmetrized at ∣B∣ = 0.5 T, the map in g is antisymmetrized at ∣B∣ = 0.1 T, and the map in j is acquired at B = + 0.5 T but not antisymmetrized. k-o, Schematics of the phase diagram for each device. Blue corresponds to four-fold degeneracy, green corresponds to two-fold degeneracy, and orange indicates no remaining degeneracy. The dark gray lines denote CI states. The light gray coloring corresponds to experimentally inaccessible regions of the phase diagram.

Extended Data Fig. 3 Incipient CI states at v = 1 and 3 in device D3.

a, ρ map surrounding the CI states in device D3 at T = 20 mK. b, ρ(T) acquired where the v = 1 CI state is most resistive. A weak metal-insulator transition is observed at T ≈ 150 mK. c, ρ(T) of the v = 3 CI state, exhibiting a metal-insulator transition at T ≈ 2.5 K.

Extended Data Fig. 4 Transport near the halo regions in devices D1 and D2.

a, ρ map in device D2 at T = 2 K, exhibiting a CI state at v = 2 and a halo feature. b, ρ(T) as a function of D at fixed v, acquired along the dashed red line in a. An arch-like feature is observed, similar to the behavior of device D3 shown in Fig. 2a. c, ρ map in device D1 at T = 2 K. A very weak CI state is observed at v = 2, as well as a distorted halo feature. d, ρ(T) acquired at the point marked by the red circle in c. Despite weaker correlations, an abrupt drop in ρ(T) is still observed to accompany the formation of the symmetry-broken halo region.

Extended Data Fig. 5 Transport at B∣∣ = 9 T in devices D2 and D3.

Maps of ρ at T = 2 K in devices a, D3 and b, D2, along with corresponding antisymmetrized Rxy in c and d. A small out-of-plane B component is also added in b-d in order to perform the (anti)-symmetrization.

Supplementary information

Supplementary Information

Supplementary Sections 1–3 and Figs.1–8.

Source data

Source Data Fig. 1

Source data for Fig.1b–g.

Source Data Fig. 2

Source data for Fig. 2.

Source Data Fig. 3

Source data for Fig. 3.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

He, M., Li, Y., Cai, J. et al. Symmetry breaking in twisted double bilayer graphene. Nat. Phys. 17, 26–30 (2021). https://doi.org/10.1038/s41567-020-1030-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41567-020-1030-6

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