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Related papers: A Reconfigurable Gate Architecture for Si/SiGe Qua…

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We propose and demonstrate experimentally a novel design of single-electron quantum dots. The structure consists of a narrow band gap quantum well that can undergo a transition from the hole accumulation regime to the electron inversion…

Other Condensed Matter · Physics 2009-11-11 G. M. Jones , B. H. Hu , C. H. Yang , M. J. Yang , Y. B. Lyanda-Geller

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…

We report low-temperature transport measurements through a double quantum dot device in a configuration where one of the quantum dots is coupled directly to the source and drain electrodes, and a second (side-coupled) quantum dot interacts…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 D. Y. Baines , T. Meunier , D. Mailly , A. D. Wieck , C. Bäuerle , L. Saminadayar , Pablo S. Cornaglia , Gonzalo Usaj , C. A. Balseiro , D. Feinberg

Time-resolved electron dynamics in coupled quantum dots is directly observed by a pulsed-gate technique. While individual gate voltages are modulated with periodic pulse trains, average charge occupations are measured with a nearby quantum…

Mesoscale and Nanoscale Physics · Physics 2010-11-12 D. Harbusch , S. Manus , H. P. Tranitz , W. Wegscheider , S. Ludwig

We present quantum transport measurements of interacting parallel quantum dots formed in the strands of a carbon nanotube rope. In this molecular quantum dot system, transport is dominated by one quantum dot, while additional resonances…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Karin Goß , Martin Leijnse , Sebastian Smerat , Maarten R. Wegewijs , Claus M. Schneider , Carola Meyer

We have studied interactions between two capacitively coupled GaAs/AlGaAs few-electron double quantum dots. Each double quantum dot defines a tunable two-level system, or qubit, in which a single excess electron occupies either the ground…

Mesoscale and Nanoscale Physics · Physics 2009-07-15 K. D. Petersson , C. G. Smith , D. Anderson , P. Atkinson , G. A. C. Jones , D. A. Ritchie

The long term scaling prospects for solid-state quantum computing architectures relies heavily on the ability to simply and reliably measure and control the coherent electron interaction strength, known as the tunnel coupling, $t_c$. Here,…

Reliable detection of single electron tunneling in quantum dots (QD) is paramount to use this category of device for quantum information processing. Here, we report charge sensing in a degenerately phosphorus-doped silicon QD by means of a…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 A. Rossi , T. Ferrus , W. Lin , T. Kodera , D. A. Williams , S. Oda

Electron transport experiments on two lateral quantum dots coupled in series are reviewed. An introduction to the charge stability diagram is given in terms of the electrochemical potentials of both dots. Resonant tunneling experiments show…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 W. G. van der Wiel , S. De Franceschi , J. M. Elzerman , T. Fujisawa , S. Tarucha , L. P. Kouwenhoven

Single semiconductor quantum dots have been widely studied within devices that can apply an electric field. In the most common system, the low energy offset between the InGaAs quantum dot and the surrounding GaAs material limits the…

Quantum Physics · Physics 2012-03-28 R. B. Patel , A. J. Bennett , I. Farrer , C. A. Nicoll , D. A. Ritchie , A. J. Shields

A semiconductor quintuple quantum dot with two charge sensors and an additional contact to the center dot from an electron reservoir is fabricated to demonstrate the concept of scalable architecture. This design enables formation of the…

Quantum spin Hall insulators, recently realized in HgTe/(Hg,Cd)Te quantum wells, support topologically protected, linearly dispersing edge states with spin-momentum locking. A local magnetic exchange field can open a gap for the edge…

Mesoscale and Nanoscale Physics · Physics 2013-05-30 Carsten Timm

With gate-defined electrostatic traps fabricated on a double quantum well we are able to realize an optically active and voltage-tunable quantum dot confining individual, long-living, spatially indirect excitons. We study the transition…

Mesoscale and Nanoscale Physics · Physics 2012-04-17 G. J. Schinner , J. Repp , E. Schubert , A. K. Rai , D. Reuter , A. D. Wieck , A. O. Govorov , A. W. Holleitner , J. P. Kotthaus

We study the ballistic edge-channel transport in quantum wires with a magnetic quantum dot, which is formed by two different magnetic fields B^* and B_0 inside and outside the dot, respectively. We find that the electron states located near…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 H. -S. Sim , G. Ihm , N. Kim , K. J. Chang

Tunnel-coupled pairs of optically active quantum dots - quantum dot molecules (QDMs) - offer the possibility to combine excellent optical properties such as strong light-matter coupling with two-spin singlet-triplet ($S-T_0$) qubits having…

Quantum computation based on semiconductor electron-spin qubits requires high control of tunnel-couplings, both across quantum dots and between the quantum dot and the reservoir. The tunnel-coupling to the reservoir sets the qubit detection…

Mesoscale and Nanoscale Physics · Physics 2018-10-30 Jan Klos , Fabian Hassler , Pascal Cerfontaine , Hendrik Bluhm , Lars R. Schreiber

We show that two electrons confined in a square semiconductor quantum dot have two isolated low-lying energy eigenstates, which have the potential to form the basis of scalable computing elements (qubits). Initialisation, one-qubit and…

Quantum Physics · Physics 2009-11-07 J. H. Jefferson , M. Fearn , D. L. J. Tipton , T. P. Spiller

We study a system of two symmetrical capacitively coupled quantum dots, each coupled to its own metallic lead, focusing on its evolution as a function of the gate voltage applied to each dot. Using the numerical renormalization group and…

Strongly Correlated Electrons · Physics 2007-05-23 Andrew K. Mitchell , Martin R. Galpin , David E. Logan

We report the fabrication and measurement of one-electron single and double quantum dots with fast tunnel rates in a Si/SiGe heterostructure. Achieving fast tunnel rates in few-electron dots can be challenging, in part due to the large…

Mesoscale and Nanoscale Physics · Physics 2011-04-07 Madhu Thalakulam , C. B. Simmons , B. M. Rosemeyer , D. E. Savage , M. G. Lagally , Mark Friesen , S. N. Coppersmith , M. A. Eriksson

In traditional approaches of obtaining quantized acoustoelectric current, a narrow channel is fabricated to form quantum dots, which hold a fixed number of electrons at a certain depth. We propose a natural way of forming quantum dots…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Xiang-Song Chen