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In stacks of two-dimensional crystals, mismatch of their lattice constants and misalignment of crystallographic axes lead to formation of moir\'{e} patterns. We show that moir\'{e} superlattice effects persist in twisted bilayer graphene…

The electronic properties of twisted bilayer graphene (TBG) can be dramatically different from those of a single graphene layer, in particular when the two layers are rotated relative to each other by a small angle. TBG has recently…

Scattering mechanisms in graphene are critical to understanding the limits of signal-to-noise-ratios of unsuspended graphene devices. Here we present the four-probe low frequency noise (1/f) characteristics in back-gated single layer…

Mesoscale and Nanoscale Physics · Physics 2010-08-05 Guangyu Xu , Carlos M. Torres , Yuegang Zhang , Fei Liu , Emil B. Song , Minsheng Wang , Yi Zhou , Caifu Zeng , Kang L. Wang

Here we present a theoretical analysis (applicable to all twist angles of TBG) of band dispersion and density of states in TBG relating evolution of flat band and Van-Hove singularities with evolution of interlayer coupling in TBG. A simple…

Mesoscale and Nanoscale Physics · Physics 2024-08-09 Veerpal , B. R. K. Nanda , Ajay

We report a local minimum in thermal conductivity in twisted bilayer graphene (TBG) at the angle of 1.08$^\circ$, which corresponds to the 'magic angle' in the transition of several other reported properties. Within the supercell of a…

Mesoscale and Nanoscale Physics · Physics 2024-09-12 Yajuan Cheng , Zheyong Fan , Tao Zhang , Masahiro Nomura , Sebastian Volz , Guimei Zhu , Baowen Li , Shiyun Xiong

Minimally twisted bilayer graphene in the presence of an interlayer bias develops a triangular network of valley chiral modes that propagate along the $AB/BA$ interfaces and scatter at the $AA$ regions. The low energy physics of the…

Mesoscale and Nanoscale Physics · Physics 2023-12-07 P. Wittig , F. Dominguez , C. De Beule , P. Recher

Electron wavefunctions in twisted bilayer graphene may have a strong single layer character or be intrinsically delocalized between layers, with their nature often determined by how energetically close they are to the Dirac point. In this…

Mesoscale and Nanoscale Physics · Physics 2014-10-06 Chi-Ken Lu , H. A. Fertig

In the presence of a finite interlayer displacement field bilayer graphene has an energy gap that is dependent on stacking and largest for the stable AB and BA stacking arrangements. When the relative orientations between layers are twisted…

Mesoscale and Nanoscale Physics · Physics 2018-07-11 Dmitry K. Efimkin , Allan H. MacDonald

We formulate a low energy effective Hamiltonian to study superlattices in bilayer graphene (BLG) using a minimal model which supports quadratic band touching points. We show that a one dimensional (1D) periodic modulation of the chemical…

Mesoscale and Nanoscale Physics · Physics 2011-08-23 Matthew Killi , Si Wu , Arun Paramekanti

We study the effect of an in-plane magnetic field on the non-interacting dispersion of twisted bilayer graphene. Our analysis is rooted in the chirally symmetric continuum model, whose zero-field band structure hosts exactly flat bands and…

Strongly Correlated Electrons · Physics 2020-05-20 Yves H. Kwan , S. A. Parameswaran , S. L. Sondhi

An unconventional insulating phase and a superconducting phase were recently discovered in the twisted bilayer graphene [Y. Cao et al, Nature {\bf 556}, 80; {\bf 556}, 43 (2018)], but the relevant low-energy electronic states have not been…

Mesoscale and Nanoscale Physics · Physics 2019-05-02 Long Zhang

Superlattices from twisted graphene mono- and bi-layer systems give rise to on-demand many-body states such as Mott insulators and unconventional superconductors. These phenomena are ascribed to a combination of flat bands and strong…

Twisted bilayer graphene (TBG) features strongly correlated and topological phases due to its flat bands emerging near the magic angle. However, the effects of the non-Hermiticity, arising from the coupling to the environment and…

Mesoscale and Nanoscale Physics · Physics 2025-06-06 Juan Pablo Esparza , Vladimir Juricic

In twisted bilayer graphene (TBG) devices, local strains frequently coexist and intertwine with the twist-angle-dependent moir\'e superlattice, significantly influencing the electronic properties of TBG, yet their combined effects remain…

We show that the twisted graphene bilayer can reveal unusual topological properties at low energies, as a consequence of a Dirac-point splitting. These features rely on a symmetry analysis of the electron hopping between the two layers of…

Mesoscale and Nanoscale Physics · Physics 2011-07-21 R. de Gail , M. O. Goerbig , F. Guinea , G. Montambaux , A. H. Castro Neto

We theoretically study the energy and optical absorption spectra of alternating twist multilayer graphene (ATMG) under a perpendicular electric field. We obtain analytically the low-energy effective Hamiltonian of ATMG up to pentalayer in…

Mesoscale and Nanoscale Physics · Physics 2024-06-28 Kyungjin Shin , Yunsu Jang , Jiseon Shin , Jeil Jung , Hongki Min

We derive the Hamiltonian for trilayer moir\'e systems with the Coulomb interaction projected onto the bands near the charge neutrality point. Motivated by the latest experimental results, we focus on the twisted symmetric trilayer graphene…

Strongly Correlated Electrons · Physics 2021-05-19 Dumitru Călugăru , Fang Xie , Zhi-Da Song , Biao Lian , Nicolas Regnault , B. Andrei Bernevig

We present a novel approach to achieve spatial variations in the degree of non-covalent functionalization of twisted bilayer graphene (tBLG). The tBLG with twist angles varying between ~ 5{\deg} and 7{\deg} was non-covalently functionalized…

We construct a heavy fermion representation for twisted bilayer graphene (TBG) systems. Two local orbitals (per spin/valley) are analytically found, which are exactly the maximally localized zero modes of the continuum Hamiltonian near the…

Strongly Correlated Electrons · Physics 2022-12-20 Hao Shi , Xi Dai

We propose that the electronic structure of twisted bilayer graphene (TBG) can be understood as Dirac fermions coupled with opposite pseudo magnetic fields generated by the moir\'e pattern. The two low-energy flat bands from each monolayer…

Mesoscale and Nanoscale Physics · Physics 2019-04-24 Jianpeng Liu , Junwei Liu , Xi Dai