The in-plane DC conductivity of twisted bilayer graphene (TBLG) is calculatedusing an expansion of the real-space Kubo-Bastin conductivity in terms ofChebyshev polynomials. We investigate within a tight-binding (TB) approach thetransport properties as a function of rotation angle, applied perpendicularelectric field and vacancy disorder. We find that for high-angle twists, thetwo layers are effectively decoupled, and the minimum conductivity at the Diracpoint corresponds to double the value observed in monolayer graphene. Thisremains valid even in the presence of vacancies, hinting that chiral symmetryis still preserved. On the contrary, for low twist angles, the conductivity atthe Dirac point depends on the twist angle and is not protected in the presenceof disorder. Furthermore, for low angles and in the presence of an appliedelectric field, we find that the chiral boundary states emerging between AB andBA regions contribute to the DC conductivity, despite the appearance ofstrongly localized states in the AA regions. The results agree with recentconductivity experiments on twisted bilayer graphene.
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