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

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We study a double quantum dot (DQD) coupled to a strongly biased quantum point contact (QPC), each embedded in independent electric circuits. For weak interdot tunnelling we observe a finite current flowing through the unbiased Coulomb…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 V. S. Khrapai , S. Ludwig , J. P. Kotthaus , H. P. Tranitz , W. Wegscheider

Full counting statistics of electron transport is of fundamental importance for a deeper understanding of the underlying physical processes in quantum transport in nanoscale devices. The backaction effect from a detector on the nanoscale…

Mesoscale and Nanoscale Physics · Physics 2013-11-01 Zeng-Zhao Li , Chi-Hang Lam , Ting Yu , J. Q. You

We study theoretically transitions of a double quantum-dot qubit caused by nonequilibrium charge fluctuations in a nearby quantum point contact (QPC) used as a detector. We show that these transitions are related to the fundamental…

Mesoscale and Nanoscale Physics · Physics 2010-05-05 C. E. Young , A. A. Clerk

We report our study of the real-time charge counting statistics measured by a quantum point contact (QPC) coupled to a single quantum dot (QD) under different back-action strength. By tuning the QD-QPC coupling or QPC bias, we controlled…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 HaiOu Li , Ming Xiao , Gang Cao , Cheng Zhou , RuNan Shang , Tao Tu , GuangCan Guo , GuoPing Guo , HongWen Jiang

We study the dynamics of a single electron spin in a double quantum dot (DQD) and its readout via a quantum point contact (QPC). We model the system microscopically and derive rate equations for the reduced electron density matrix of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jian-Ping Zhang , Shi-Hua Ouyang , Chi-Hang Lam , J. Q. You

We briefly overview our recent results on nonequilibrium interactions between neighboring electrically isolated nanostructures. One of the nanostructures is represented by an externally biased quantum point contact (drive-QPC), which is…

Mesoscale and Nanoscale Physics · Physics 2008-11-25 V. S. Khrapai , S. Ludwig , J. P. Kotthaus , H. P. Tranitz , W. Wegscheider

We study the interaction between two adjacent but electrically isolated quantum point contacts (QPCs). At high enough source-drain bias on one QPC, the drive QPC, we detect a finite electric current in the second, unbiased, detector QPC.…

Mesoscale and Nanoscale Physics · Physics 2007-09-03 V. S. Khrapai , S. Ludwig , J. P. Kotthaus , H. P. Tranitz , W. Wegscheider

The quantum point contact (QPC) back-action has been found to cause non-thermal-equilibrium excitations to the electron spin states in a quantum dot (QD). Here we use back-action as an excitation source to probe the spin excited states…

Mesoscale and Nanoscale Physics · Physics 2011-12-13 HaiOu Li , Ming Xiao , Gang Cao , Cheng Zhou , RuNan Shang , Tao Tu , GuangCan Guo , HongWen Jiang , GuoPing Guo

Quantum point contacts (QPCs) are commonly employed to capacitively detect the charge state of coupled quantum dots (QD). An indirect back-action of a biased QPC onto a double QD laterally defined in a GaAs/AlGaAs heterostructure is…

Mesoscale and Nanoscale Physics · Physics 2010-07-01 D. Harbusch , D. Taubert , H. P. Tranitz , W. Wegscheider , S. Ludwig

Interactions between nanoscale semiconductor structures form the basis for charge detectors in the solid state. Recent experimental advances have demonstrated the on-chip detection of single electron transport through a quantum dot (QD).…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Eugene V. Sukhorukov , Andrew N. Jordan , Simon Gustavsson , Renaud Leturcq , Thomas Ihn , Klaus Ensslin

We derive an analytical expression for the backaction dephasing rate, which characterizes the disturbance induced by coupling with an environment containing a quantum dot detector (QDD). In this letter, we show that charge noise induces…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Toshihiro Kubo , Yasuhiro Tokura

We investigate a tunnel contact coupled to a double quantum dot (DQD) and employed as charge monitor for the latter. We consider both the classical limit and the quantum regime. In the classical case, we derive measurement correlations from…

Mesoscale and Nanoscale Physics · Physics 2014-10-16 Robert Hussein , Jorge Gómez-García , Sigmund Kohler

We study the nonequilibrium properties of an electronic circuit composed of a double quantum dot (DQD) channel coupled to a quantum point contact (QPC) within the framework of stochastic thermodynamics. We show that the transition rates…

Mesoscale and Nanoscale Physics · Physics 2015-10-28 Gregory Bulnes Cuetara , Massimiliano Esposito

Achieving low-error, exchange-interaction operations in quantum dots for quantum computing imposes simultaneous requirements on the exchange energy's dependence on applied voltages. A double quantum dot (DQD) qubit, approximated with a…

Strongly Correlated Electrons · Physics 2013-05-29 Erik Nielsen , Ralph W. Young , Richard P. Muller , M. S. Carroll

Detector backaction can be completely evaded when the state of a one-electron quantum cyclotron is detected, but it nonetheless significantly broadens the quantum-jump resonance lineshapes from which the cyclotron frequency can be deduced.…

Atomic Physics · Physics 2021-02-19 Xing Fan , Gerald Gabrielse

We report on devices based on graphene charge detectors (CDs) capacitively coupled to graphene and carbon nanotube quantum dots (QDs). We focus on back action effects of the CD on the probed QD. A strong influence of the bias voltage…

Mesoscale and Nanoscale Physics · Physics 2023-07-19 C. Volk , S. Engels , C. Neumann , C. Stampfer

It was proposed that a double quantum dot can be used to be a detector of spin bias. Electron transport through a double quantum dot is investigated theoretically when a pure spin bias is applied on two conducting leads contacted to the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Qing-feng Sun , Yanxia Xing , Shun-Qing Shen

We study the two-qubit controlled-not gate operating on qubits encoded in the spin state of a pair of electrons in a double quantum dot. We assume that the electrons can tunnel between the two quantum dots encoding a single qubit, while…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Dimitrije Stepanenko , Guido Burkard

Electron charge transport through a quantum point contact (QPC) driven by an asymmetric spin bias is studied. A large charge current is induced when the transmission coefficient of the QPC jumps from one integer plateau to the next.…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yanxia Xing , Qing-feng Sun , Jian Wang

We present the experimental realization of a Quantum Dot (QD) operating as a high-frequency noise detector. Current fluctuations produced in a nearby Quantum Point Contact (QPC) ionize the QD and induce transport through excited states. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 E. Onac , F. Balestro , L. H. Willems van Beveren , U. Hartmann , Y. V. Nazarov , L. P. Kouwenhoven
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