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Related papers: Quantum dots in Si/SiGe 2DEGs with Schottky top-ga…

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A new fabrication technique is used to produce quantum dots with read-out channels in silicon/silicon-germanium two-dimensional electron gases. The technique utilizes Schottky gates, placed on the sides of a shallow etched quantum dot, to…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 M. R. Sakr , E. Yablonovitch , E. T. Croke , H. W. Jiang

A split gate technique is used to form a lateral quantum dot in a two-dimensional electron gas of a modulation-doped silicon/silicon-germanium heterostructure. e-beam lithography was employed to produce split gates. By applying negative…

For high-electron-mobility transistors based on two-dimensional electron gas (2DEG) within a quantum well, such as those based on AlGaN/GaN heterostructure, a Schottky-gate is used to maximize the amount of charge that can be induced and…

We report on the realization and top-gating of a two-dimensional electron system in a nuclear spin free environment using 28Si and 70Ge source material in molecular beam epitaxy. Electron spin decoherence is expected to be minimized in…

Mesoscale and Nanoscale Physics · Physics 2009-01-19 J. Sailer , V. Lang , G. Abstreiter , G. Tsuchiya , K. M. Itoh , J. W. Ager , E. E. Haller , D. Kupidura , D. Harbusch , S. Ludwig , D. Bougeard

We report the fabrication and electrical characterization of a single electron transistor in a modulation doped silicon/silicon-germanium heterostructure. The quantum dot is fabricated by electron beam lithography and subsequent reactive…

We report on the effects of a global top gate on low-frequency noise in Schottky gate-defined quantum point contacts (QPCs) and quantum dots (QDs) in a modulation-doped Si/SiGe heterostructure. For a relatively large top gate voltage, the…

Mesoscale and Nanoscale Physics · Physics 2013-04-02 K. Takeda , T. Obata , Y. Fukuoka , W. M. Akhtar , J. Kamioka , T. Kodera , S. Oda , S. Tarucha

Enhancement-mode Si/SiGe electron quantum dots have been pursued extensively by many groups for \revEdit{their} potential in quantum computing. Most of the reported dot designs utilize multiple metal-gate layers and use Si/SiGe…

Mesoscale and Nanoscale Physics · Physics 2016-09-21 T. M. Lu , J. K. Gamble , R. P. Muller , E. Nielsen , D. Bethke , G. A. Ten Eyck , T. Pluym , J. R. Wendt , J. Dominguez , M. P. Lilly , M. S. Carroll , M. C. Wanke

We employ density functional theory to calculate the self consistent electronic structure, free energy and linear source-drain conductance of a lateral semiconductor quantum dot patterned via surface gates on the 2DEG formed at the…

Condensed Matter · Physics 2009-10-28 M. Stopa

Molecular beam epitaxy is employed to manufacture self-assembled InAs/GaAs quantum dot Schottky resonant tunneling diodes. By virtue of a thin AlAs insertion barrier, the thermal current is effectively reduced and electron resonant…

Mesoscale and Nanoscale Physics · Physics 2007-12-07 Jie Sun , Peng Jin , Chang Zhao , Like Yu , Xiaoling Ye , Bo Xu , Yonghai Chen , Zhanguo Wang

We report a robust process for fabrication of surface-gated Si/SiGe quantum dots (QDs) with an integrated superconducting single-electron transistor (S-SET) charge sensor. A combination of a deep mesa etch and AlOx backfill is used to…

Mesoscale and Nanoscale Physics · Physics 2011-04-08 Mingyun Yuan , Feng Pan , Zhen Yang , T. J. Gilheart , Fei Chen , D. E. Savage , M. G. Lagally , M. A. Eriksson , A. J. Rimberg

We report the fabrication and electrical characterization of depletion-mode quantum dots in a two-dimensional hole gas (2DHG) in intrinsic silicon. We use fixed charge in a SiO$_2$/Al$_2$O$_3$ dielectric stack to induce a 2DHG at the…

Mesoscale and Nanoscale Physics · Physics 2018-02-06 Sergey V. Amitonov , Paul C. Spruijtenburg , Max W. S. Vervoort , Wilfred G. van der Wiel , Floris A. Zwanenburg

We propose and demonstrate a relaxed-SiGe/strained-Si (SiGe/s-Si) enhancement-mode gate stack for quantum dots. The enhancement-mode SiGe/s-Si structure is pursued because it spaces the quantum dot away from charge and spin defect rich…

Mesoscale and Nanoscale Physics · Physics 2011-07-28 T. M. Lu , N. C. Bishop , T. Pluym , J. Means , P. G. Kotula , J. Cederberg , L. A. Tracy , J. Dominguez , M. P. Lilly , M. S. Carroll

We implement silicon quantum dot devices with two layers of gate electrodes using a self-alignment technique, which allows for ultra-small gate lengths and intrinsically perfect layer-to-layer alignment. In a double quantum dot system, we…

We report the realization of a hybrid superconductor-quantum dot device by means of top-down nanofabrication starting from a two dimensional electron gas in a InGaAs/InAlAs semiconductor heterostructure. The quantum dot is defined by…

Mesoscale and Nanoscale Physics · Physics 2011-04-15 Fabio Deon , Vittorio Pellegrini , Francesco Giazotto , Giorgio Biasiol , Lucia Sorba , Fabio Beltram

Transport measurements at cryogenic temperatures through a few electron top gated quantum dot fabricated in a silicon/silicon-germanium heterostructure are reported. Variations in gate voltage induce a transition from an isolated dot toward…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Levente J. Klein , Donald E. Savage , Mark A. Eriksson

We report the realization of nanotube-based quantum dot structures that use local electrostatic gating to produce individually controllable dots in series along a nanotube. Electrostatic top-gates produce depletion regions in the underlying…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 M. J. Biercuk , S. Garaj , N. Mason , J. M. Chow , C. M. Marcus

Metallization of Schottky surface gates by sputtering Au on strained Si/SiGe heterojunctions enables the depletion of the two dimensional electron gas (2DEG) at a relatively small voltage while maintaining an extremely low level of leakage…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 G. D. Scott , M. Xiao , E. T. Croke , E. Yablonovitch , H. W. Jiang

We report on the fabrication and electronic transport characterisation of Schottky-gated strongly confined Si/SiGe quantum point contacts (QPC). At zero magnetic field and T=450mK the QPC conductance as a function of gate voltage shows a…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 G. Scappucci , L. Di Gaspare , E. Giovine , A. Notargiacomo , R. Leoni , F. Evangelisti

Metal-semiconductor interfaces, known as Schottky junctions, have long been hindered by defects and impurities. Such imperfections dominate the electrical characteristics of the junction by pinning the metal Fermi energy. We report…

Mesoscale and Nanoscale Physics · Physics 2018-11-08 Samuel W. LaGasse , Prathamesh Dhakras , Takashi Taniguchi , Kenji Watanabe , Ji Ung Lee

We fabricated strongly confined Schottky-gated quantum point contacts by etching Si/SiGe heterostructures and observed intriguing conductance quantization in units of approximately 1e2/h. Non-linear conductance measurements were performed…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 G. Scappucci , L. Di Gaspare , E. Giovine , A. Notargiacomo , R. Leoni , F. Evangelisti
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