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Related papers: Backaction of a charge detector on a double quantu…

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We report on the realization of a few-electron double quantum dot defined in a two-dimensional electron gas by means of surface gates on top of a GaAs/AlGaAs heterostructure. Two quantum point contacts (QPCs) are placed in the vicinity of…

We consider the capacitive interaction between a charge qubit and a sensor quantum dot(SQD) perturbatively to the second order of their coupling constant at zero temperature by utilizing the method of non-equilibrium Green's functions…

Mesoscale and Nanoscale Physics · Physics 2017-07-12 S. Mojtaba Tabatabaei

Bound-state (BS) formation in quantum point contacts (QPCs) may offer a convenient way to localize and probe single spins. In this letter, we investigate how such BSs are affected by monitoring them with a second QPC, which is coupled to…

Strongly Correlated Electrons · Physics 2009-11-13 Y. Yoon , M. -G. Kang , T. Morimoto , L. Mourokh , N. Aoki , J. L. Reno , J. P. Bird , Y. Ochiai

Quantum dots are artificial atoms used for a multitude of purposes. Charge defects are commonly present and can significantly perturb the designed energy spectrum and purpose of the dots. Voltage controlled exchange energy in silicon double…

Mesoscale and Nanoscale Physics · Physics 2012-03-21 Rajib Rahman , Erik Nielsen , Richard P. Muller , Malcolm S. Carroll

Most quantum point contacts (QPCs) fabricated in high-mobility 2D electron gases show a zero-bias conductance peak near pinchoff, but the origin of this peak remains a mystery. Previous experiments have primarily focused on the zero-bias…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Y. Ren , W. W. Yu , S. M. Frolov , J. A. Folk , W. Wegscheider

A theoretical study is reported of electron transport at finite temperature in a double quantum dot (DQD) capacitively coupled to a quantum point contact (QPC). Starting from a Hamiltonian model, a master equation is obtained for the…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Gregory Bulnes Cuetara , Massimiliano Esposito , Gernot Schaller , Pierre Gaspard

In a single quantum dot (QD), the electrons were driven out of thermal equilibrium by the back-action from a nearby quantum point contact (QPC). We found the driving to energy excited states can be probed with the random telegraph signal…

Mesoscale and Nanoscale Physics · Physics 2015-03-19 Gang Cao , Ming Xiao , HaiOu Li , Cheng Zhou , RuNan Shang , Tao Tu , GuangCan Guo , GuoPing Guo , HongWen Jiang

Quantum point contact or QPC -- a constriction in a semiconducting two-dimensional (2D) electron system with a quantized conductance -- has been found as the building block of novel spintronic, and topological electronic circuits. They can…

Quantum point contact (QPC), one of the typical mesoscopic transport devices, has been suggested to be an efficient detector for quantum measurement. In the context of two-state charge qubit, our previous studies showed that the QPC's…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Xue-Ning Hu , Xin-Qi Li

We theoretically study the conditional counting statistics of electron transport through a system consisting of a single quantum dot (SQD) or coherently coupled double quantum dots (DQD's) monitored by a nearby quantum point contact (QPC)…

Mesoscale and Nanoscale Physics · Physics 2017-12-01 Yen-Jui Chang , Tsung-Kang Yeh , Chao-Hung Wan , D. Wahyu Utami , Gerard J. Milburn , Hsi-Sheng Goan

We investigate experimentally the quantum coherence of an electronic two-level system in a double quantum dot under continuous charge detection. The charge-state of the two-level system is monitored by a capacitively coupled single quantum…

We consider a mechanism of spin decay for an electron spin in a quantum dot due to coupling to a nearby quantum point contact (QPC) with and without an applied bias voltage. The coupling of spin to charge is induced by the spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Massoud Borhani , Vitaly N. Golovach , Daniel Loss

We consider a double-quantum-dot (DQD) qubit which contains six electrons instead of the usual one or two. In this spin qubit, quantum information is encoded in a low-lying singlet-triplet space much as in the case of a two-electron DQD…

Mesoscale and Nanoscale Physics · Physics 2013-11-21 Erik Nielsen , Edwin Barnes , J. P. Kestner , S. Das Sarma

High-fidelity detection of charge transitions in quantum dots (QDs) is a key ingredient in solid state quantum computation. We demonstrate high-bandwidth radio-frequency charge detection in bilayer graphene quantum dots (QDs) using a…

The coherent time evolution of electrons in double quantum dots induced by fast bias-voltage switches is studied theoretically. As it was shown experimentally, such driven double quantum dots are potential devices for controlled…

Mesoscale and Nanoscale Physics · Physics 2011-04-14 Alexander Croy , Ulf Saalmann

It is shown that the resonance Kondo tunneling through a double quantum dot (DQD) with even occupation and singlet ground state may arise at a strong bias, which compensates the energy of singlet/triplet excitation. Using the…

Strongly Correlated Electrons · Physics 2007-05-23 M. N. Kiselev , K. Kikoin , L. W. Molenkamp

We investigated the electron transport properties of parallel-coupled double quantum dot (DQD) devices under magnetic fields. When a low magnetic field was applied, electron tunneling through parallel-coupled DQDs was observed. Under a high…

Mesoscale and Nanoscale Physics · Physics 2021-10-13 Tsuyoshi Hatano , Toshihiro Kubo , Shinichi Amaha , Yasuhiro Tokura , Seigo Tarucha

The dynamic capture of electrons in a semiconductor quantum dot (QD) by raising a potential barrier is a crucial stage in metrological quantized charge pumping. In this work, we use a quantum point contact (QPC) charge sensor to study…

Mesoscale and Nanoscale Physics · Physics 2018-09-27 S. P. Giblin , P. See , A. Petrie , T. J. B. M. Janssen , I. Farrer , J. P. Griffiths , G. A. C. Jones , D. A. Ritchie , M. Kataoka

We obtain the finite-temperature unconditional master equation of the density matrix for two coupled quantum dots (CQD) when one dot is subjected to a measurement of its electron occupation number using a point contact (PC). To determine…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Hsi-Sheng Goan , G. J. Milburn , H. M. Wiseman , He Bi Sun

We investigate electronic transport through parallel double quantum dot(DQD) system with strong on-site Coulomb interaction and capacitive interdot coupling. By applying numerical renormalization group(NRG) method, the ground state of the…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Guo-Hui Ding , Fei Ye , Bing Dong