Terahertz conductivity of twisted bilayer graphene

Abstract

Using terahertz time-domain spectroscopy, the real part of optical conductivity [${\sigma }_1(\omega )$] of twisted bilayer graphene was obtained at different temperatures (10 -- 300 K) in the frequency range 0.3 -- 3 THz. On top of a Drude-like response, we see a strong peak in ${\sigma }_1(\omega )$ at $\sim$2.7 THz. We analyze the overall Drude-like response using a disorder-dependent (unitary scattering) model, then attribute the peak at 2.7 THz to an enhanced density of states at that energy, that is caused by the presence of a van Hove singularity arising from a commensurate twisting of the two graphene layers.

4 figures, 5 pages

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Cited by in corpus (8)

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• Near-field thermal transport between twisted bilayer graphene
• Electron-phonon scattering and in-plane electric conductivity in twisted bilayer graphene
• Terahertz Circular Dichroism in Commensurate Twisted Bilayer Graphene
• Photon absorption in twisted bilayer graphene
• Controlling quantum spin Hall state via strain in various stacking bilayer phosphorene