title: Terahertz conductivity of twisted bilayer graphene.
abstract: Using terahertz time-domain spectroscopy, the real part of optical conductivity [σ(1)(ω)] 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 σ(1)(ω) at ~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, which is caused by the presence of a van Hove singularity arising from a commensurate twisting of the two graphene layers.
authors: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore.
authors: Xingquan
authors: X
authors: Zou
authors: Jingzhi
authors: J
authors: Shang
authors: Jianing
authors: J
authors: Leaw
authors: Zhiqiang
authors: Z
authors: Luo
authors: Liyan
authors: L
authors: Luo
authors: Chan
authors: C
authors: La-o-Vorakiat
authors: Liang
authors: L
authors: Cheng
authors: S A
authors: SA
authors: Cheong
authors: Haibin
authors: H
authors: Su
authors: Jian-Xin
authors: JX
authors: Zhu
authors: Yanpeng
authors: Y
authors: Liu
authors: Kian Ping
authors: KP
authors: Loh
authors: A H
authors: AH
authors: Castro Neto
authors: Ting
authors: T
authors: Yu
authors: Elbert E M
authors: EE
authors: Chia