We investigate the bandwidth compression due to out of plane pressure of the moire flatbands near charge neutrality in twisted bilayer graphene for a continuous range of small rotation angles of up to ∼2.5∘. The flatband bandwidth minima angles are found to grow linearly with interlayer coupling {\omega} and decrease with Fermi velocity. Application of moderate pressure values of up to 2.5 GPa achievable through a hydraulic press should allow accessing a flatband for angles as large as ∼1.5^{\circ}insteadof\sim 1 \circatzeropressure.ThisreductionofthemoireˊpatternlengthforlargertwistangleimpliesanincreaseoftheeffectiveCoulombinteractionscalepermoirecellbyabout50\sim 2$ the elastic energy that resists the commensuration strains due to the moire pattern. Our results suggest that application of pressure on twisted bilayer graphene nanodevices through a hydraulic press will notably facilitate the device preparation efforts required for exploring the ordered phases near magic angle flatbands.
@article{arxiv.1808.00104,
title = {Pressure Induced Compression of Flatbands in Twisted Bilayer Graphene},
author = {Bheema Lingam Chittari and Nicolas Leconte and Srivani Javvaji and Jeil Jung},
journal= {arXiv preprint arXiv:1808.00104},
year = {2019}
}