DataVXAdvanced MaterialsPaper
journal article·2021-12Open access

Unraveling Strain Gradient Induced Electromechanical Coupling in Twisted Double Bilayer Graphene Moiré Superlattices

Yuhao Li, Xiao Wang, Deqi Tang, Xi Wang, Kenji Watanabe, Takashi Taniguchi, Daniel R. Gamelin, David H. Cobden, Matthew Yankowitz, Xiaodong Xu, Jiangyu Li

Advanced Materials· Volume 33· Issue 51
Publisher pageOpen full text
Source abstract

Abstract

Abstract Moiré superlattices of 2D materials with a small twist angle are thought to exhibit appreciable flexoelectric effect, though unambiguous confirmation of their flexoelectricity is challenging due to artifacts associated with commonly used piezoresponse force microscopy (PFM). For example, unexpectedly small phase contrast (≈8°) between opposite flexoelectric polarizations is reported in twisted bilayer graphene (tBG), though theoretically predicted value is 180°. Here a methodology is developed to extract intrinsic moiré flexoelectricity using twisted double bilayer graphene (tDBG) as a model system, probed by lateral PFM. For small twist angle samples, it is found that a vectorial decomposition is essential to recover the small intrinsic flexoelectric response at domain walls from a large background signal. The obtained threefold symmetry of commensurate domains with significant flexoelectric response at domain walls is fully consistent with the theoretical calculations. Incommensurate domains in tDBG with relatively large twist angles can also be observed by this technique. A general strategy is provided here for unraveling intrinsic flexoelectricity in van der Waals moiré superlattices while providing insights into engineered symmetry breaking in centrosymmetric materials.
Source: crossref · Quality: baseline

Research context

Nanomaterials

OpenAlex topics: Nonlocal and gradient elasticity in micro/nano structures · Graphene research and applications · Multiferroics and related materials

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Department of Physics University of Washington Seattle WA 98195 USA

Department of Materials Science and Engineering Southern University of Science and Technology Shenzhen Guangdong 518055 China

Shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen Guangdong 518055 China

Department of Chemistry University of Washington Seattle WA 98195 USA

Research Center for Functional Materials National Institute for Materials Science 1‐1 Namiki Tsukuba 305‐0044 Japan

International Center for Materials Nanoarchitectonics National Institute for Materials Science 1‐1 Namiki Tsukuba 305‐0044 Japan

Department of Materials Science and Engineering University of Washington Seattle WA 98195 USA

Guangdong Provisional Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology Shenzhen Guangdong 518055 China

Funding

National Key Research and Development Program of China · Leading Talents Program of Guangdong Province · National Natural Science Foundation of China · Core Research for Evolutional Science and Technology · China Scholarship Council

References (50)

Show source-provided references
1. 10.1038/s41567-020-0906-910.1038/s41567-020-0906-9 ↗
2. 10.1038/nature2616010.1038/nature26160 ↗
3. 10.1126/science.aaw378010.1126/science.aaw3780 ↗
4. 10.1126/science.aay553310.1126/science.aay5533 ↗
5. 10.1038/s41586-021-03409-210.1038/s41586-021-03409-2 ↗
6. 10.1038/s41565-020-0708-310.1038/s41565-020-0708-3 ↗
7. 10.1038/s41567-020-1030-610.1038/s41567-020-1030-6 ↗
8. 10.1038/s41586-020-2458-710.1038/s41586-020-2458-7 ↗
9. 10.1038/s41567-020-0825-910.1038/s41567-020-0825-9 ↗
10. 10.1016/j.pmatsci.2019.05.00310.1016/j.pmatsci.2019.05.003 ↗
11. 10.1063/1.135644410.1063/1.1356444 ↗
12. 10.1007/s10853-005-5916-610.1007/s10853-005-5916-6 ↗
13. 10.1063/1.142669010.1063/1.1426690 ↗
14. 10.1063/1.497901510.1063/1.4979015 ↗
15. 10.1063/1.474293310.1063/1.4742933 ↗
16. 10.1038/ncomms857210.1038/ncomms8572 ↗
17. 10.1016/j.cap.2016.12.01210.1016/j.cap.2016.12.012 ↗
18. 10.1038/s41467-020-20667-210.1038/s41467-020-20667-2 ↗
19. Vizner Stern M. · Science · 2021
20. 10.1126/science.abd323010.1126/science.abd3230 ↗
21. 10.1146/annurev-matsci-071312-12163410.1146/annurev-matsci-071312-121634 ↗
22. 10.1063/1.236298410.1063/1.2362984 ↗
23. 10.1103/PhysRevLett.97.03680310.1103/PhysRevLett.97.036803 ↗
24. 10.1038/nphys295410.1038/nphys2954 ↗
25. 10.1038/s41563-019-0346-z10.1038/s41563-019-0346-z ↗
26. 10.1103/PhysRevLett.123.19770210.1103/PhysRevLett.123.197702 ↗
27. 10.1103/PhysRevB.86.24543410.1103/PhysRevB.86.245434 ↗
28. 10.1016/j.ssc.2007.02.01310.1016/j.ssc.2007.02.013 ↗
29. 10.1016/j.susc.2013.01.00510.1016/j.susc.2013.01.005 ↗
30. 10.1073/pnas.201736611810.1073/pnas.2017366118 ↗
31. 10.1088/2053-1583/aa964010.1088/2053-1583/aa9640 ↗
32. 10.1038/nmat248810.1038/nmat2488 ↗
33. 10.1016/j.jmps.2010.03.00110.1016/j.jmps.2010.03.001 ↗
34. 10.1103/PhysRevLett.14.21710.1103/PhysRevLett.14.217 ↗
35. 10.1038/nmat375410.1038/nmat3754 ↗
36. Fei Z. · Nature · 2018
37. 10.1063/1.489764710.1063/1.4897647 ↗
38. Shu L. · J. Appl. Phys. · 2011 · 110
39. 10.1002/adma.20120385210.1002/adma.201203852 ↗
40. 10.1016/j.jmat.2015.03.00110.1016/j.jmat.2015.03.001 ↗
41. 10.1103/PhysRevLett.117.11680410.1103/PhysRevLett.117.116804 ↗
42. 10.1021/acs.nanolett.5b0526310.1021/acs.nanolett.5b05263 ↗
43. 10.1007/s10853-005-5946-010.1007/s10853-005-5946-0 ↗
44. 10.1016/j.nanoen.2018.07.05010.1016/j.nanoen.2018.07.050 ↗
45. 10.1103/PhysRevB.54.1116910.1103/PhysRevB.54.11169 ↗
46. 10.1016/0927-0256(96)00008-010.1016/0927-0256(96)00008-0 ↗
47. 10.1103/PhysRevB.59.175810.1103/PhysRevB.59.1758 ↗
48. 10.1103/PhysRevB.50.1795310.1103/PhysRevB.50.17953 ↗
49. 10.1103/PhysRevLett.77.386510.1103/PhysRevLett.77.3865 ↗
50. 10.1063/1.338234410.1063/1.3382344 ↗