检索结果-南通市图书馆

Twistronics in graphene-based van der Waals structures

在线全文

学校读者我要写书评

暂无评论

引用

Chinese Physics B 2020年第11期29卷 1-16页

作者： Ya-Ning Ren Yu Zhang Yi-Wen Liu Lin He Center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China

The electronic properties of van der Waals(vd W) structures can be substantially modified by the moiré superlattice potential, which strongly depends on the twist angle among the compounds. In twisted bilayer graphene(TBG), two lowenergy Van Hove singularities(VHSs) move closer with decreasing twist angles and finally become highly non-dispersive flat bands at the magic angle(~1.1°). When the Fermi level lies within the flat bands of the TBG near the magic angle,Coulomb interaction is supposed to exceed the kinetic energy of the electrons, which can drive the system into various strongly correlated phases. Moreover, the strongly correlated states of flat bands are also realized in other graphene-based vd W structures with an interlayer twist. In this article, we mainly review the recent scanning tunneling microscopy(STM)advances on the strongly correlated physics of the magic-angle TBG(MATBG) and the small-angle twisted multilayer graphene. Lastly we will give out a perspective of this field.

关键词： twisted bilayer graphene correlated states superconductivity

Emergence of correlations in twisted monolayer-trilayer graphene heterostructures

在线全文

学校读者我要写书评

暂无评论

引用

中国物理B:英文版 2023年第9期32卷 74-78页

作者：周璋 Kenji Watanabe Takashi Taniguchi 林晓毛金海高鸿钧 School of Physical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100049China Advanced Materials Laboratory National Institute for Materials ScienceTsukuba305-0044Japan Institute of Physics Chinese Academy of SciencesBeijing 100190China

Twisted bilayer graphene heterostructures have recently emerged as a well-established platform for studying strongly correlated phases,such as correlated insulating,superconducting,and topological *** this notion to twisted multilayer graphene heterostructures has exhibited more diverse correlated phases,as some fundamental properties related to symmetry and band structures are correspondingly ***,we report the observations of correlated states in twisted monolayer-trilayer(Bernal stacked)graphene *** phases at integer fillings of the moire unit cell are revealed at a high displacement field and stabilized with a moderate magnetic field on the electron-doping side at a twist angle of 1.45°,where the lift of degeneracy at the integer fillings is observed in the Landau fan *** results demonstrate the effectiveness of moire engineering in an extended structure and provide insights into electric-field tunable correlated phases.

关键词： twisted multilayer graphene correlated states electric tuning

Tunable correlation in twisted monolayer–trilayer graphene

在线全文

学校读者我要写书评

暂无评论

引用

Chinese Physics B 2023年第6期32卷 96-101页

作者：丁冬冬牛锐锐韩香岩曲壮壮王知雨李卓贤刘倩伶韩春蕊路建明 State Key Laboratory for Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Institute of Microelectronics Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Flat-band physics of moirésuperlattices,originally discovered in the celebrated twisted bilayer graphene,have recently been intensively explored in multilayer graphene systems that can be further controlled by electric *** this work,we experimentally find the evidence of correlated insulators at half filling of the electron moiréband of twisted monolayer–trilayer graphene with a twist angle around 1.2°.Van Hove singularity(VHS),manifested as enhanced resistance and zero Hall voltage,is observed to be distinct in conduction and valence flat *** also depends on the direction and magnitude of the displacement fields,consistent with the asymmetric crystal *** the resistance ridges at VHS can be enhanced by magnetic fields,when they cross commensurate fillings of the moirésuperlattice in the conduction band,the enhancement is so strong that signatures of correlated insulator appear,which may further develop into an energy gap depending on the correlation *** last,Fermi velocity derived from temperature coefficients of resistivity is compared between conduction and valence bands with different displacement *** is found that electronic correlation has a negative dependence on the Fermi velocity,which in turn could be used to quantify the correlation strength.

关键词： twisted multilayer graphene heterostructure correlated states van Hove singularity