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Related papers: Topological confinement in bilayer graphene

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We present a combined experimental and theoretical study of twisted double bilayer graphene with twist angles between 1{\deg} and 1.35{\deg}. Consistent with moir\'e band structure calculations, we observe insulators at integer moir\'e band…

Mesoscale and Nanoscale Physics · Physics 2019-11-25 G. William Burg , Jihang Zhu , Takashi Taniguchi , Kenji Watanabe , Allan H. MacDonald , Emanuel Tutuc

Spontaneous symmetry-breaking, where the ground state of a system has lower symmetry than the underlying Hamiltonian, is ubiquitous in physics. It leads to multiply-degenerate ground states, each with a different "broken" symmetry labeled…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Jonathan S. Alden , Adam W. Tsen , Pinshane Y. Huang , Robert Hovden , Lola Brown , Jiwoong Park , David A. Muller , Paul L. McEuen

We demonstrate by experiments and numerical simulations that the low-temperature current-voltage characteristics in diffusive bilayer graphene (BLG) exhibit a strong superlinearity at finite bias voltages. The superlinearity is weakly…

Mesoscale and Nanoscale Physics · Physics 2011-05-24 J. K. Viljas , A. Fay , M. Wiesner , P. J. Hakonen

Twisted bilayer graphene (tBLG) forms a quasicrystal whose structural and electronic properties depend on the angle of rotation between its layers. Here we present a scanning tunneling microscopy study of gate-tunable tBLG devices supported…

Understanding the mechanisms governing the optical activity of layered-stacked materials is crucial to the design of devices aimed at manipulating light at the nanoscale. Here, we show that both twisted and slid bilayer graphene are chiral…

Mesoscale and Nanoscale Physics · Physics 2020-11-30 V. Nam Do , H. Anh Le , V. Duy Nguyen , D. Bercioux

Divergent density of states offers the unique opportunity to explore a wide variety of correlated electron physics. In the thinnest limit, this has been predicted and verified in the ultra-flat bands of magic-angle twisted bilayer graphene,…

Mesoscale and Nanoscale Physics · Physics 2022-08-15 Anna M. Seiler , Fabian R. Geisenhof , Felix Winterer , Kenji Watanabe , Takashi Taniguchi , Tianyi Xu , Fan Zhang , R. Thomas Weitz

Quantum confined devices that manipulate single electrons in graphene are emerging as attractive candidates for nanoelectronics applications. Previous experiments have employed etched graphene nanostructures, but edge and substrate disorder…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Monica T. Allen , Jens Martin , Amir Yacoby

Higher-order topological insulators, as a novel family of topological phases, are a hot frontier in condensed matter physics due to their adherence to unconventional bulk-boundary correspondence. A three-dimensional second-order topological…

Mesoscale and Nanoscale Physics · Physics 2024-06-18 Han-Rong Xia , Jia-Zheng Li , Si-Yu Yuan , Meng Xiao

Chiral edge states of 2+1 dimensional Abelian and non-Abelian topological phases can be represented by chiral conformal field theories with integer and non-integer values of central charge, respectively. In this work we describe certain…

High Energy Physics - Theory · Physics 2019-10-16 Carlos A. Hernaski , Pedro R. S. Gomes

Bilayer graphene encapsulated in tungsten diselenide can host a weak topological phase with pairs of helical edge states. The electrical tunability of this phase makes it an ideal platform to investigate unique topological effects at zero…

Bilayer graphene subjected to perpendicular magnetic and electric fields displays a subtle competition between different symmetry broken phases, resulting from an interplay between the internal spin and valley degrees of freedom. The…

Strongly Correlated Electrons · Physics 2015-04-14 Kusum Dhochak , Efrat Shimshoni , Erez Berg

We analytically describe the plasmonic edge modes for an interface that involves the twisted bilayer graphene (TBG) or other similar Moire van der Waals heterostructure. For this purpose, we employ a spatially homogeneous, isotropic and…

Mesoscale and Nanoscale Physics · Physics 2021-09-21 Dionisios Margetis , Tobias Stauber

Materials with flat electronic bands often exhibit exotic quantum phenomena owing to strong correlations. Remarkably, an isolated low-energy flat band can be induced in bilayer graphene by simply rotating the layers to 1.1$^{\circ}$,…

Mesoscale and Nanoscale Physics · Physics 2019-01-29 Matthew Yankowitz , Shaowen Chen , Hryhoriy Polshyn , K. Watanabe , T. Taniguchi , David Graf , Andrea F. Young , Cory R. Dean

We present the results for the evolution of the Fermi surfaces under variation of number density and displacement field for spin and valley-polarized states in Bernal bilayer graphene (BBG) using a realistic form of the electronic…

Strongly Correlated Electrons · Physics 2025-04-04 R. David Mayrhofer , Andrey V. Chubukov

Rhombohedral multilayer graphene is a physical realization of the chiral two-dimensional electron gas that can host zero-line modes (ZLMs), also known as kink states, when the local ap opened by inversion symmetry breaking potential changes…

Mesoscale and Nanoscale Physics · Physics 2016-10-03 Changhee Lee , Gunn Kim , Jeil Jung , Hongki Min

Electronic localization is numerically studied in disordered bilayer graphene with an electric-field induced energy gap. Bilayer graphene is a zero-gap semiconductor, in which an energy gap can be opened and controlled by an external…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Mikito Koshino

Bilayer graphene samples may exhibit regions where the two layers are locally delaminated forming a so-called quantum blister in the graphene sheet. Electron and hole states can be confined in this graphene quantum blisters (GQB) by…

Mesoscale and Nanoscale Physics · Physics 2018-08-15 Hasan M. Abdullah , H. Bahlouli , F. M. Peeters , B. Van Duppen

We show that the flat bands in the chiral model of magic-angle twisted bilayer graphene remain exactly flat in the presence of a perpendicular magnetic field. This is shown by an exact mapping between the model and the lowest Landau level…

Strongly Correlated Electrons · Physics 2021-09-29 Yarden Sheffer , Ady Stern

We study the edge spectrum of twisted sheets of single layer and bilayer graphene in cases where the continuum model predicts a valley Chern insulator -- an insulating state in which the occupied moir\'e mini-bands from each valley have a…

Mesoscale and Nanoscale Physics · Physics 2023-03-08 Ahmed Khalifa , Ganpathy Murthy , Ribhu K. Kaul

We study how the electronic structure of the bilayer graphene (BLG) is changed by electric field and strain from {\it ab initio} density-functional calculations using the LMTO and the LAPW methods. Both hexagonal and Bernal stacked…

Materials Science · Physics 2010-03-10 B. R. K. Nanda , S. Satpathy