Twisted bilayer graphene (tBLG) represents a family of unique materials with optoelectronic properties tuned by the rotation angle between the two layers. The presented work shows an additional way of tweaking the electronic structure of tBLG: by modifying the interlayer 2 distance, for example by a small uniaxial out-of-plane compression. We have focused on the optical transition energy, which shows a clear dependence on the interlayer distance, both experimentally and theoretically.

In this work we explore mechanical properties of graphene samples of variable thickness. For this purpose, we coupled a high pressure sapphire anvil cell to a microRaman spectrometer. From the evolution of the G band frequency with stress, we document the importance the substrate has on the mechanical response of graphene. On the other hand, the appearance of disorder as a consequence of the stress treatment has a negligible effect on the high stress behavior of graphene.Isotopic labeled twisted bilayer graphene under compression characterized by Raman spectroscopy.

Abstract. The stability properties of the bipenalty method presented in Reference [4] is studied in application to one-dimensional bipenalized Signorini problem. The attention has been paid on the critical Courant numbers estimation based on Gershgorin's theorem. It is shown that Gershgorin's formula overestimates maximum eigenfrequency for all penalty ratios with exception of the critical penalty ratio. Thus, smaller safer values of critical Courant numbers are obtained in comparison with exact ones calculated from the solution of eigenvalue problem.

No abstract

No abstract