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Related papers: Quantum Hall effect in graphene with twisted bilay…

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We theoretically study the electronic structure of small-angle twisted bilayer graphene with a large potential asymmetry between the top and bottom layers. We show that the emergent helical states known to appear on the triangular AB-BA…

Mesoscale and Nanoscale Physics · Physics 2020-03-18 Bonnie Tsim , Nguyen N. T. Nam , Mikito Koshino

This article reviews the theoretical and experimental work related to the electronic properties of bilayer graphene systems. Three types of bilayer stackings are discussed: the AA, AB, and twisted bilayer graphene. This review covers…

Mesoscale and Nanoscale Physics · Physics 2016-10-25 A. V. Rozhkov , A. O. Sboychakov , A. L. Rakhmanov , Franco Nori

We report the observation of a quantum anomalous Hall effect in twisted bilayer graphene showing Hall resistance quantized to within .1\% of the von Klitzing constant $h/e^2$ at zero magnetic field.The effect is driven by intrinsic strong…

Strongly Correlated Electrons · Physics 2020-03-18 M. Serlin , C. L. Tschirhart , H. Polshyn , Y. Zhang , J. Zhu , K. Watanabe , T. Taniguchi , L. Balents , A. F. Young

We investigate the electronic confinement in bilayer graphene by topological loops of different shapes. These loops are created by lateral gates acting via gap inversion on the two graphene sheets. For large-area loops the spectrum is well…

Mesoscale and Nanoscale Physics · Physics 2022-01-12 Nassima Benchtaber , David Sánchez , Llorenç Serra

The quantum anomalous Hall effect (QAHE) is a robust topological phenomenon featuring quantized Hall resistance at zero magnetic field. We report the QAHE in a rhombohedral pentalayer graphene/monolayer WS2 heterostructure. Distinct from…

Mesoscale and Nanoscale Physics · Physics 2024-05-14 Tonghang Han , Zhengguang Lu , Yuxuan Yao , Jixiang Yang , Junseok Seo , Chiho Yoon , Kenji Watanabe , Takashi Taniguchi , Liang Fu , Fan Zhang , Long Ju

The non-interacting energy spectrum of graphene and its bilayer counterpart consists of multiple degeneracies owing to the inherent spin, valley and layer symmetries. Interactions among charge carriers are expected to spontaneously break…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 R. Thomas Weitz , Monica T. Allen , Benjamin E. Feldman , Jens Martin , Amir Yacoby

We study the behavior of the extended states of a two-dimensional electron system in silicon in a magnetic field, B. Our results show that the extended states, corresponding to the centers of different Landau levels, merge with the lowest…

Condensed Matter · Physics 2016-08-31 S. V. Kravchenko , Whitney Mason , J. E. Furneaux , V. M. Pudalov

In this article we briefly review recent experimental and theoretical work on quantum Hall effect in graphene, and argue that some of the quantum Hall states exhibit spontaneous symmetry breaking that is driven by electron-electron…

Mesoscale and Nanoscale Physics · Physics 2007-06-13 Kun Yang

We report the first experimental study of the quantum interference correction to the conductivity of bilayer graphene. Low-field, positive magnetoconductivity due to the weak localisation effect is investigated at different carrier…

Mesoscale and Nanoscale Physics · Physics 2007-08-14 R. V. Gorbachev , F. V. Tikhonenko , A. S. Mayorov , D. W. Horsell , A. K. Savchenko

Bernal-stacked multilayer graphene is a versatile platform to explore quantum transport phenomena and interaction physics due to its exceptional tunability via electrostatic gating. For instance, upon applying a perpendicular electric…

Mesoscale and Nanoscale Physics · Physics 2022-05-11 F. Winterer , A. M. Seiler , A. Ghazaryan , F. R. Geisenhof , K. Watanabe , T. Taniguchi , M. Serbyn , R. T. Weitz

The most celebrated property of the quantum spin Hall effect is the presence of spin-polarized counter-propagating edge states. This novel edge state configuration has also been predicted to occur in graphene when spin-split electron- and…

Mesoscale and Nanoscale Physics · Physics 2013-02-19 Patrick Maher , Cory R. Dean , Andrea F. Young , Takashi Taniguchi , Kenji Watanabe , Kenneth L. Shepard , James Hone , Philip Kim

We report on transport measurements of dual-gated, single-layer graphene devices in the quantum Hall regime, allowing for independent control of the filling factors in adjoining regions. Progress in device quality allows us to study…

Mesoscale and Nanoscale Physics · Physics 2014-05-15 F. Amet , J. R. Wiliams , K. Watanabe , T. Taniguchi , D. Goldhaber-Gordon

Remarkable recent experiments have observed fractional quantum anomalous Hall (FQAH) effects at zero field and unusually high temperatures in twisted semiconductor bilayer $t$MoTe$_2$. Intriguing observations in these experiments such as…

Mesoscale and Nanoscale Physics · Physics 2024-04-03 Ahmed Abouelkomsan , Aidan P. Reddy , Liang Fu , Emil J. Bergholtz

Quantum anomalous Hall effect (QAHE) is a fundamental quantum transport phenomenon in condensed matter physics. Until now, the only experimental realization of the QAHE has been observed for Cr/V-doped (Bi,Sb)$_2$Te$_3$ but at extremely low…

Mesoscale and Nanoscale Physics · Physics 2018-06-08 Xinzhou Deng , Hualing Yang , Shifei Qi , Xiaohong Xu , Zhenhua Qiao

We investigate the transport properties of high-quality single-layer graphene, epitaxially grown on a 6H-SiC(0001) substrate. We have measured transport properties, in particular charge carrier density, mobility, conductivity and…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Johannes Jobst , Daniel Waldmann , Florian Speck , Roland Hirner , Duncan K. Maude , Thomas Seyller , Heiko B. Weber

Inspired by experiments on magic angle twisted bilayer graphene, we present a lattice mean-field model for the quantum anomalous Hall effect in a moir\'e setting. Our hopping model thus provides a simple route to a moir\'e Chern insulator…

Mesoscale and Nanoscale Physics · Physics 2023-07-05 Ahmed Khalifa , Ganpathy Murthy , Ribhu K. Kaul

We report observations of well developed half integer quantum Hall effect (QHE) on mono layer graphene films of 7 mm \times 7 mm in size. The graphene films are grown by chemical vapor deposition (CVD) on copper, then transferred to SiO_{2}…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 Tian Shen , Wei Wu , Qingkai Yu , Curt A Richter , Randolph Elmquist , David Newell , Yong P. Chen

Transmission profiles in bilayer graphene have been studied theoretically in presence of a pair of delta function magnetic barriers. Two types of asymmetric Fano resonances are discussed in connection to the electronic cloaking effect in…

Mesoscale and Nanoscale Physics · Physics 2017-11-21 S. Maiti , R. Biswas , C. Sinha

We consider a fractional quantum Hall bilayer system with an interface between quantum Hall states of filling fractions $(\nu_{\text{top}},\nu_{\text{bottom}})=(1,1)$ and $(1/3,2)$, motivated by a recent approach to engineering artificial…

Mesoscale and Nanoscale Physics · Physics 2019-06-19 Jukka I. Väyrynen , Moshe Goldstein , Yuval Gefen

We investigate the electronic transport properties of unbiased and biased bilayer graphene nanoribbon in n-p and n-n junctions subject to a perpendicular magnetic field. Using the non-equilibrium Green's function method and the…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 H. Hatami , N. Abedpour , A. Qaiumzadeh , Reza Asgari