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تسجيل مستخدم جديدPressure Induced Compression of Flatbands in Twisted Bilayer Graphene
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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 $sim2.5^{circ}$. 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 $sim 1.5$^{circ}$ instead of $sim 1 circ$ at zero pressure. This reduction of the moire pattern length for larger twist angle implies an increase of the effective Coulomb interaction scale per moire cell by about 50% and enhance roughly by a factor of $sim 2$ 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.
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