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Graphene field-effect transistors are fabricated utilizing single-crystal hexagonal boron nitride (h-BN), an insulating isomorph of graphene, as the gate dielectric. The devices exhibit mobility values exceeding 10,000 cm2/V-sec and current…

Mesoscale and Nanoscale Physics · Physics 2016-11-18 I. Meric , C. R. Dean , A. F. Young , J. Hone , P. Kim , K. L. Shepard

In this article, we have theoretically investigated the performance of graphene-hexagonal Boron Nitride hyper crystals to demonstrate all angle negative refraction.Hexagonal Boron Nitride, the latest natural hyperbolic material; can be a…

Rational design of artificial lattices yields effects unavailable in simple solids, and vertical superlattices of multilayer semiconductors are already used in optical sensors and emitters. Manufacturing lateral superlattices remains a much…

We perform electrical transport measurements in graphene with several sample geometries. In particular, we design ``invasive'' probes crossing the whole graphene sheet as well as ``external'' probes connected through graphene side arms. The…

Mesoscale and Nanoscale Physics · Physics 2008-12-07 B. Huard , N. Stander , J. A. Sulpizio , D. Goldhaber-Gordon

Transport measurement of electron optics in monolayer graphene p-n junction devices has been traditionally studied with negative refraction and chiral transmission experiments in Hallbar magnetic focusing set-ups. We show direct signatures…

Mesoscale and Nanoscale Physics · Physics 2022-10-20 Mirza M. Elahi , Yihang Zeng , Cory R. Dean , Avik W. Ghosh

The flat bands in bilayer graphene(BLG) are sensitive to electric fields E\bot directed between the layers, and magnify the electron-electron interaction effects, thus making BLG an attractive platform for new two-dimensional (2D) electron…

Mesoscale and Nanoscale Physics · Physics 2012-03-23 J. Velasco , L. Jing , W. Bao , Y. Lee , P. Kratz , V. Aji , M. Bockrath , C. N. Lau , C. Varma , R. Stillwell , D. Smirnov , Fan Zhang , J. Jung , A. H. MacDonald

We present a thermal annealing study on single-layer and bilayer (BLG) graphene encapsulated in hexagonal boron nitride. The samples are characterized by electron transport and Raman spectroscopy measurements before and after each annealing…

Mesoscale and Nanoscale Physics · Physics 2018-05-07 S. Engels , B. Terrés , F. Klein , S. Reichardt , M. Goldsche , S. Kuhlen , K. Watanabe , T. Taniguchi , C. Stampfer

A series of measurements using a technique called electrostatic-manipulation scanning tunneling microscopy (EM-STM) were performed on a highly-oriented pyrolytic graphite surface. The electrostatic interaction between the STM tip and the…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 P. Xu , Y. Yang , D. Qi , S. D. Barber , J. K. Schoelz , M. L. Ackerman , L. Bellaiche , P. M. Thibado

In this work we compare two fundamentally different approaches to the electronic transport in deformed graphene: a) the condensed matter approach in which current flow paths are obtained by applying the non-equilibrium Green's function…

Mesoscale and Nanoscale Physics · Physics 2016-05-23 Thomas Stegmann , Nikodem Szpak

Graphene grown via chemical vapour deposition (CVD) on copper foil has emerged as a high-quality, scalable material, that can be easily integrated on technologically relevant platforms to develop promising applications in the fields of…

Semiconductor nanostructures based on two dimensional electron gases (2DEGs) have the potential to provide new approaches to sensing, information processing, and quantum computation. Much is known about electron transport in 2DEG…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. A. Topinka , B. J. LeRoy , R. M. Westervelt , S. E. J. Shaw , R. Fleischmann , E. J. Heller , K. D. Maranowski , A. C. Gossard

Electron correlation in graphene is unique because of the interplay of the Dirac cone dispersion of $\pi$ electrons with long range Coulomb interaction. The random phase approximation predicts no metallic screening at long distance and low…

Materials Science · Physics 2017-10-23 Huihuo Zheng , Yu Gan , Peter Abbamonte , Lucas K. Wagner

Electroluminescence, a non-thermal radiative process, is ubiquitous in semi-conductors and insulators but fundamentally precluded in metals. We show here that this restriction can be circumvented in high-quality graphene. By investigating…

Based on a tight-binding model and a recursive Green's function technique, spin-depentent ballistic transport through tinny graphene sheets (flakes) is studied. The main interest is focussed on: electrical conductivity, giant…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 S. Krompiewski

The effect of an hexagonal boron nitride (hBN) layer close aligned with twisted bilayer graphene (TBG) is studied. At sufficiently low angles between twisted bilayer graphene and hBN, $\theta_{hBN} \lesssim 2^\circ$, the graphene electronic…

Strongly Correlated Electrons · Physics 2020-10-28 Tommaso Cea , Pierre A. Pantaleon , Francisco Guinea

Encapsulating graphene in hexagonal Boron Nitride has several advantages: the highest mobilities reported to date are achieved in this way, and precise nanostructuring of graphene becomes feasible through the protective hBN layers.…

Mesoscale and Nanoscale Physics · Physics 2021-01-04 Yongping Du , Ning Xu , Xianqing Lin , Antti-Pekka Jauho

We demonstrate high-resolution modification of suspended multi-layer graphene sheets by controlled exposure to the focused electron beam of a transmission electron microscope. We show that this technique can be used to realize, on…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Michael D. Fischbein , Marija Drndic

Confinement of electrons in graphene to make devices has proven to be a challenging task. Electrostatic methods fail because of Klein tunneling, while etching into nanoribbons requires extreme control of edge terminations, and bottom-up…

Mesoscale and Nanoscale Physics · Physics 2018-04-03 Y. Wu , D. Zhai , C. Pan , B. Cheng , T. Taniguchi , K. Watanabe , N. Sandler , M. Bockrath

Devices made from two dimensional materials such as graphene and transition metal dichalcogenides exhibit remarkable electronic properties of interest to many subdisciplines of nanoscience. Owing to their 2D nature, their quality is highly…

Mesoscale and Nanoscale Physics · Physics 2019-11-12 Michael A. Altvater , Shuang Wu , Zhenyuan Zhang , Tianhui Zhu , Guohong Li , Kenji Watanabe , Takashi Taniguchi , Eva Y. Andrei

We measure electron transport through point contacts in an electron gas in AlGaAs/GaAs heterostructures and graphene for a range of temperatures, magnetic fields and electron densities. We find a magnetoconductance peak around B = 0. With…