| AVS 63rd International Symposium & Exhibition | |
| 2D Materials Focus Topic | Monday Sessions |
| Session 2D+MI+SA-MoM |
| Session: | 2D Materials Characterization including Microscopy and Spectroscopy |
| Presenter: | Paul Thibado, University of Arkansas |
| Authors: | P. Thibado, University of Arkansas M. Ackerman, University of Arkansas P. Kumar, University of Arkansas S. Singh, University of Arkansas M. Neek-Amal, University of Antwerp, Belgium F. Peeters, University of Antwerp, Belgium |
| Correspondent: | Click to Email |
Local, long-time evolution measurements of the height fluctuations of a 2D membrane allows examination of the fundamental foundations of statistical mechanics in soft condensed matter. However, such measurements have proved elusive, thereby forcing critical theoretical assumptions in our best models. We report sub-nanometer, high-bandwidth height measurements of freestanding graphene using constant-current, point-mode scanning tunneling microscopy, as a follow-up to our previous related works [1-2]. By tracking atoms directly, the ability to measure dynamic events is increased by a factor of 1000 over the present state-of-the-art membrane imaging technology. Surprisingly, the membrane velocities follow the Cauchy-Lorentz distribution consistent with a Lévy process, rather than the expected Maxwell-Boltzmann distribution. We also present molecular dynamics simulations, which illustrate spontaneous mirror buckling events that give rise to the long excursions.
Acknowledgements:
This work was supported in part by Office of Naval Research (USA) under Grant No. N00014-10-1-0181 and National Science Foundation (USA) under Grant No. DMR- 0855358.
References:
[1] P. Xu, M. Neek-Amal, S.D. Barber, J.K. Schoelz, M.L. Ackerman, P.M. Thibado, A. Sadeghi, and F.M. Peeters, Nature Comm. 5, 3720 (2014).
[2] M. Neek-Amal, P. Xu, J.K. Schoelz, M.L. Ackerman, S.D. Barber, P.M. Thibado, A. Sadeghi, and F.M. Peeters, Nature Comm. 5, 4962 (2014).