@article{be66e935394646c6868e09612698802b,
title = "Rotational stability of twisted bilayer graphene",
abstract = "Moir{\'e} superlattices form in twisted graphene bilayers due to periodic regions of commensurability, but truncation of the moir{\'e} patterns affects the rotational stability of finite-sized sheets. Here, we report the stepwise untwisting of nanometer-sized bilayer graphene flakes at elevated temperatures, each step corresponding to a potential energy barrier formed by changes to the commensurability between the moir{\'e} superlattice and flake size with twist angle. The number of locally stable energy states and their barrier energies scale with the flake size, allowing twisted graphene flakes of several tens of nanometers to remain thermally stable even at chemical vapor deposition temperatures.",
author = "S. Bagchi and Johnson, {H. T.} and Chew, {H. B.}",
note = "S.B. and H.B.C. acknowledge the support provided by Dr. A. Sayir under the AFOSR Aerospace Materials for Extreme Environment Program (Award No. FA9550-19-1-0242). H.J. acknowledges the support of the Army Research Office (Award No. W911NF-17-1-0544) Material Science Division under Dr. C. Varanasi, and support from NSF Award No. CMMI 18\u201325300 (MOMS program). Many fruitful discussions with collaborators and group members of H.J., including Dr. P. Pochet, Prof. E. Ertekin, Dr. S. Zhu, and E. Annevelink, are gratefully acknowledged. We acknowledge computational time provided by the Blue Waters sustained-petascale computing project, which is supported by the National Science Foundation (Awards No. OCI-0725070 and No. ACI-1238993) and the state of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications.",
year = "2020",
month = feb,
day = "1",
doi = "10.1103/PhysRevB.101.054109",
language = "English (US)",
volume = "101",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "5",
}