English
Related papers

Related papers: Tunable capacitive inter-dot coupling in a bilayer…

200 papers

Large scale quantum computers will consist of many interacting qubits. In this paper we expand the two flux qubit coupling scheme first devised in [Phys. Rev. B {\bf 70}, 140501 (2004)] and realized in [Science {\bf 314}, 1427 (2006)] to a…

Quantum Physics · Physics 2013-05-29 Peter Groszkowski , Austin G. Fowler , Felix Motzoi , Frank K. Wilhelm

Quantum states in graphene are four-fold degenerate: two fold in spins, and two fold in valleys.Both degrees of freedom can be utilized for qubit preparations. In our bilayer graphene quantumdots, we demonstrate that the valley g-factorgv,…

Controlling the energy spectrum of quantum-coherent superconducting circuits, i.e. the energies of excited states, the circuit anharmonicity and the states' charge dispersion, is essential for designing performant qubits. This control is…

Double-gated graphene devices provide an important platform for understanding electrical and optical properties of graphene. Here we present transport measurements of single layer, bilayer and trilayer graphene devices with suspended top…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 J. Velasco , Y. Lee , L. Jing , G. Liu , W. Bao , C. N. Lau

Stimulated by recent advances in isolating graphene, we discovered that quantum dot can be trapped in Z-shaped graphene nanoribbon junciton. The topological structure of the junction can confine electronic states completely. By varying…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Z. F. Wang , Huaixiu Zheng , Q. W. Shi , Jie Chen , Qunxiang Li , J. G. Hou

A major challenge in the field of quantum computing is the construction of scalable qubit coupling architectures. Here, we demonstrate a novel tuneable coupling circuit that allows superconducting qubits to be coupled over long distances.…

We present Coulomb blockade measurements in a graphene double dot system. The coupling of the dots to the leads and between the dots can be tuned by graphene in-plane gates. The coupling is a non-monotonic function of the gate voltage.…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 F. Molitor , S. Dröscher , J. Güttinger , A. Jacobsen , C. Stampfer , T. Ihn , K. Ensslin

Extremely long coherence times, excellent single-qubit gate fidelities and two-qubit logic have been demonstrated with silicon metal-oxide-semiconductor spin qubits, making it one of the leading platforms for quantum information processing.…

Mesoscale and Nanoscale Physics · Physics 2020-01-14 H. G. J. Eenink , L. Petit , W. I. L. Lawrie , J. S. Clarke , L. M. K. Vandersypen , M. Veldhorst

Large-angle twisted bilayer graphene (tBLG) is known to be electronically decoupled due to the spatial separation of the Dirac cones corresponding to individual graphene layers in the reciprocal space. The close spacing between the layers…

Mesoscale and Nanoscale Physics · Physics 2023-02-28 Alina Mrenca-Kolasinska , Peter Rickhaus , Giulia Zheng , Klaus Richter , Thomas Ihn , Klaus Ensslin , Ming-Hao Liu

Graphene quantum dots provide promising platforms for hosting spin, valley, or spin-valley qubits. Taking advantage of the electrically generated band gap and the ambipolar nature, high-quality quantum dots can be defined in bilayer…

Mesoscale and Nanoscale Physics · Physics 2023-11-02 Fang-Ming Jing , Guo-Quan Qin , Zhuo-Zhi Zhang , Xiang-Xiang Song , Guo-Ping Guo

We experimentally demonstrate a tunable hybrid qubit in a five-electron GaAs double quantum dot. The qubit is encoded in the (1,4) charge regime of the double dot and can be manipulated completely electrically. More importantly, dot…

Mesoscale and Nanoscale Physics · Physics 2016-03-02 Gang Cao , Hai-Ou Li , Guo-Dong Yu , Bao-Chuan Wang , Bao-Bao Chen , Xiang-Xiang Song , Ming Xiao , Guang-Can Guo , Hong-Wen Jiang , Xuedong Hu , Guo-Ping Guo

Recent demonstrations using electron spins stored in quantum dots array as qubits are promising for developing a scalable quantum computing platform. An ongoing effort is therefore aiming at the precise control of the quantum dots…

We report electronic transport experiments on a graphene single electron transistor. The device consists of a graphene island connected to source and drain electrodes via two narrow graphene constrictions. It is electrostatically tunable by…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 C. Stampfer , E. Schurtenberger , F. Molitor , J. Guettinger , T. Ihn , K. Ensslin

Twisted graphene based moir\'e heterostructures host a flat band at the magic angles where the kinetic energy of the charge carriers is quenched and interaction effects dominate. This results in emergent phases such as superconductors and…

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…

We present gate-controlled single, double, and triple dot operation in electrostatically gapped bilayer graphene. Thanks to the recent advancements in sample fabrication, which include the encapsulation of bilayer graphene in hexagonal…

Mesoscale and Nanoscale Physics · Physics 2018-08-29 Luca Banszerus , Benedikt Frohn , Alexander Epping , Daniel Neumaier , Kenji Watanabe , Takashi Taniguchi , Christoph Stampfer

Coupled nanomechanical resonators are interesting for both fundamental studies and practical applications as they offer rich and tunable oscillation dynamics. At present, the mechanical coupling in such systems is often mediated by a fixed…

Mesoscale and Nanoscale Physics · Physics 2020-11-10 G. J. Verbiest , M. Goldsche , J. Sonntag , T. Khodkov , N. von den Driesch , D. Buca , C. Stampfer

We report integrated charge sensing measurements on a Si/SiGe double quantum dot. The quantum dot is shown to be tunable from a single, large dot to a well-isolated double dot. Charge sensing measurements enable the extraction of the tunnel…

Novel materials are in great demand for future applications. The discovery of graphene, a one atom thick carbon layer, holds the promise for unique device architectures and functionalities exploiting unprecedented physical phenomena. The…

Mesoscale and Nanoscale Physics · Physics 2011-01-25 M. F. Craciun , S. Russo , M. Yamamoto , S. Tarucha

We report on a double moir\'e system consisting of four graphene layers, where the top and bottom pairs form small-twist-angle bilayer graphene, and the middle interface has a large rotational mismatch. This system shows clear signatures of…