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Related papers: Bilayer Graphene Quantum Dot Defined by Topgates

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We investigate the transport properties of double-gated bilayer graphene nanoribbons at room temperature. The devices were fabricated using conventional CMOS-compatible processes. By analyzing the dependence of the resistance at the charge…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Bartholomaeus N. Szafranek , Daniel Schall , Martin Otto , Daniel Neumaier , Heinrich Kurz

We study electron transport in nanostructures patterned in bilayer graphene patches grown epitaxially on SiC as a function of doping, magnetic field, and temperature. Away from charge neutrality transport is only weakly modulated by changes…

The rich and electrostatically tunable phase diagram exhibited by moir\'e materials has made them a suitable platform for hosting single material multi-purpose devices. To engineer such devices, understanding electronic transport and…

A single-electron transistor has been realized in a Ga[Al]As heterostructure by oxidizing lines in the GaAs cap layer with an atomic force microscope. The oxide lines define the boundaries of the quantum dot, the in-plane gate electrodes,…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. Luescher , A. Fuhrer , R. Held , T. Heinzel , K. Ensslin , W. Wegscheider

This is a review on graphene quantum dots and their use as a host for spin qubits. We discuss the advantages but also the challenges to use graphene quantum dots for spin qubits as compared to the more standard materials like GaAs. We start…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Patrik Recher , Bjoern Trauzettel

We study quantum dots defined by external potentials within finite flakes of bilayer graphene using the tight-binding approach. We find that in the limit of large flakes containing zigzag edges the dot-localized energy levels appear within…

Mesoscale and Nanoscale Physics · Physics 2013-10-21 D. P. Żebrowski , E. Wach , B. Szafran

Quantum computers require both scalability and high performance for practical applications. While semiconductor quantum dots are promising candidates for quantum bits, the complexity of measurement setups poses an important challenge for…

Due to Klein tunneling, electrostatic confinement of electrons in graphene is not possible. This hinders the use of graphene for quantum dot applications. Only through quasi-bound states with finite lifetime has one achieved to confine…

Mesoscale and Nanoscale Physics · Physics 2018-05-29 Hasan M. Abdullah , M. Van der Donck , H. Bahlouli , F. M. Peeters , B. Van Duppen

Two strongly coupled quantum dots are theoretically and experimentally investigated. In the conductance measurements of a GaAs based low-dimensional system additional features to the Coulomb blockade have been detected at low temperatures.…

Mesoscale and Nanoscale Physics · Physics 2008-09-23 F. J. Kaiser , S. Kohler , P. Hänggi , M. Malecha , J. Ebbecke , A. Wixforth , H. W. Schumacher , B. Kästner , D. Reuter , A. D. Wieck

The unique capabilities of capacitance measurements in bilayer graphene enable probing of layer-specific properties that are normally out of reach in transport measurements. Furthermore, capacitance measurements in the top-gate and…

Mesoscale and Nanoscale Physics · Physics 2013-05-02 Andrea F. Young , Leonid S. Levitov

The magnetic field dependence of energy levels in gapped single- and bilayer graphene quantum dots (QDs) defined by electrostatic gates is studied analytically in terms of the Dirac equation. Due to the absence of sharp edges in these types…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Patrik Recher , Johan Nilsson , Guido Burkard , Bjoern Trauzettel

We perform transport measurements in high quality bilayer graphene pnp junctions with suspended top gates. At a magnetic field B=0, we demonstrate band gap opening by an applied perpendicular electric field, with an On/Off ratio up to…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Lei Jing , Jairo Velasco , Philip Kratz , Gang Liu , Wenzhong Bao , Marc Bockrath , Chun Ning Lau

We show measurements on a bilayer graphene quantum dot with an integrated charge detector. The focus lies on enabling charge detection with a 30 nm wide bilayer graphene nanoribbon located approximately 35 nm next to a bilayer graphene…

The transmission across a graphene bilayer region is calculated for two different types of connections to monolayer leads. A transfer matrix algorithm based on a tight binding model is developed to obtain the ballistic transmission beyond…

Mesoscale and Nanoscale Physics · Physics 2019-06-05 Hadi Z. Olyaei , Pedro Ribeiro , Eduardo V. Castro

Designer 2D materials where the constituent layers are not aligned may result in band structures with dispersionless, "flat" bands. Twisted bilayer graphene has been found to show correlated phases as well as superconductivity related to…

Superconductivity · Physics 2023-02-03 P. Törmä , S. Peotta , B. A. Bernevig

We introduce a novel two-dimensional electronic system with ultrastrong interlayer interactions, namely twisted bilayer graphene with a large twist angle, as an ideal ground for realizing interlayer-coherent excitonic condensates. In these…

Mesoscale and Nanoscale Physics · Physics 2022-12-20 Dohun Kim , Byungmin Kang , Yong-Bin Choi , Kenji Watanabe , Takashi Taniguchi , Gil-Ho Lee , Gil Young Cho , Youngwook Kim

We report on a method to fabricate and measure gateable molecular junctions which are stable at room temperature. The devices are made by depositing molecules inside a few-layer graphene nanogap, formed by feedback controlled…

Bilayer graphene in a perpendicular electric field can host domain walls between regions of reversed field direction or interlayer stacking. The gapless modes propagating along these domain walls, while not strictly topological,…

Mesoscale and Nanoscale Physics · Physics 2015-08-26 Benjamin J. Wieder , Fan Zhang , C. L. Kane

Metals are commonly used as electrostatic gates in devices due to their abundant charge carrier densities that are necessary for efficient charging and discharging. A semiconducting gate can be beneficial for certain fabrication processes,…

When a quantum dot is subjected to a thermal gradient, the temperature of electrons entering the dot can be determined from the dot's thermocurrent if the conductance spectrum and background temperature are known. We demonstrate this…

Materials Science · Physics 2011-09-07 E. A. Hoffmann , H. A. Nilsson , J. E. Matthews , N. Nakpathomkun , A. I. Persson , L. Samuelson , H. Linke