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Related papers: Double dot chain as a macroscopic quantum bit

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Coupled quantum dots are an example of the ubiquitous quantum double potential well. In a typical transport experiment, each quantum dot is also coupled to a continuum of states. Our approach takes this into account by using a Green's…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 D. M. Cardamone , C. A. Stafford , B. R. Barrett

A microscopic theory is used to study the optical properties of semiconductor quantum dots. The dephasing of a coherent excitation and line-shifts of the interband transitions due to carrier-carrier Coulomb interaction and carrier-phonon…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 M. Lorke , T. R. Nielsen , J. Seebeck , P. Gartner , F. Jahnke

We study spectral and transport properties of interacting quantum dots with spin. Two particular model systems are investigated: Lateral multilevel and two parallel quantum dots. In both cases different paths through the system can give…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 D. Boese , W. Hofstetter , H. Schoeller

Realising scalable quantum networks requires a meticulous level of understanding and mitigating the deleterious effects of decoherence. Many quantum device platforms feature multiple decoherence mechanisms, often with a dominant mechanism…

Quantum Physics · Physics 2023-08-17 Julian Wiercinski , Erik M. Gauger , Moritz Cygorek

Electron pairing due to a repulsive Coulomb interaction in a triple quantum dot (TQD) is experimentally studied. It is found that electron pairing in two dots of a TQD is mediated by the third dot, when the third dot strongly couples with…

Mesoscale and Nanoscale Physics · Physics 2018-07-24 Changki Hong , Gwangsu Yoo , Jinhong Park , Min-Kyun Cho , Yunchul Chung , H. -S. Sim , Dohun Kim , Hyungkook Choi , Vladimir Umansky , Diana Mahalu

Double-slit experiments inferring the phase and the amplitude of the transmission coefficient performed at quantum dots (QD), in the Coulomb blockade regime, present anomalies at the phase changes depending on the number of electrons…

Mesoscale and Nanoscale Physics · Physics 2013-05-21 A. I. Mese , A. Bilekkaya , S. Arslan , S. Aktas , A. Siddiki

Recent progress in experimental studies of low-dimensional systems with strong spin-orbit coupling poses a question on the effect of this coupling on the energy spectrum of electrons in semiconductor nanostructures. It is shown in the paper…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Emmanuel I. Rashba

Double quantum dots are one of the promising two-state quantum systems for realizing qubits. In the quest of successfully manipulating and reading information in qubit systems, it is of prime interest to control the charge response of the…

Mesoscale and Nanoscale Physics · Physics 2022-10-04 A. Crépieux , M. Lavagna

We study the transient dynamics subject to quantum coherence effects of two interacting parallel quantum dots weakly coupled to macroscopic leads. The stationary particle current of this quantum system is sensitive to perturbations much…

Mesoscale and Nanoscale Physics · Physics 2023-04-18 Stephanie Matern , Katarzyna Macieszczak , Simon Wozny , Martin Leijnse

Decoherence in quantum bit circuits is presently a major limitation to their use for quantum computing purposes. We present experiments, inspired from NMR, that characterise decoherence in a particular superconducting quantum bit circuit,…

Superconductivity · Physics 2015-06-25 G. Ithier , E. Collin , P. Joyez , P. J. Meeson , D. Vion , D. Esteve , F. Chiarello , A. Shnirman , Y. Makhlin , J. Schriefl , G. Schon

We present a study of the effects of decoherence in the operation of a discrete quantum walk on a line, cycle and hypercube. We find high sensitivity to decoherence, increasing with the number of steps in the walk, as the particle is…

Quantum Physics · Physics 2009-11-07 Viv Kendon , Ben Tregenna

We investigate the effect of the Coulomb interaction on the applicability of quantum gates on a system of two Coulomb-coupled quantum dots. We calculate the fidelity for a single- and a two-qubit gate and the creation of Bell states in the…

Mesoscale and Nanoscale Physics · Physics 2010-09-08 Juliane Danckwerts , Andreas Knorr , Carsten Weber

We examine the effect of multilevels on decoherence and dephasing properties of a quantum system consisting of a non-ideal two level subspace, identified as the qubit and a finite set of higher energy levels above this qubit subspace. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 T. Hakioglu , K. Savran

The dominant source of decoherence for an electron spin in a quantum dot is the hyperfine interaction with the surrounding bath of nuclear spins. The decoherence process may be slowed down by subjecting the electron spin to suitable…

Mesoscale and Nanoscale Physics · Physics 2017-08-23 Wenxian Zhang , V. V. Dobrovitski , Lea F. Santos , Lorenza Viola , B. N. Harmon

A quasi-one-dimensional quantum dot containing two interacting electrons is analyzed in search of signatures of chaos. The two-electron energy spectrum is obtained by diagonalization of the Hamiltonian including the exact Coulomb…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. J. Fendrik , M. J. Sánchez , P. I. Tamborenea

A model of strongly disordered lattice system with long-range Coulomb interactions between localized charge carriers has been considered. The total electronic energy is characterized by the presence of multiple metastable minima (including…

Strongly Correlated Electrons · Physics 2013-03-08 Yuri G. Pogorelov , J. M. B. Lopes dos Santos , J. M. V. P. Lopes

In this article, we consider a quantum dot system which is interacting with a spatially separated metallic gate electrode via direct Coulomb interaction. Here, the gate electrode is described by an idealized two-dimensional electron gas.…

Other Condensed Matter · Physics 2007-05-23 K. M. Indlekofer

Solid state quantum bits are a promising candidate for the realization of a scalable quantum computer, however, they are usually strongly limited by decoherence. We consider a double quantum dot charge qubit, whose basis states are defined…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 Udo Hartmann , Frank K. Wilhelm

The ability to connect distant qubits plays a fundamental role in quantum computing. Therefore, quantum systems candidates for quantum computation must be able to interact all their constituent qubits. Here, we model the quantum dot spin…

Quantum Physics · Physics 2022-10-26 Iann Cunha , Leonardo Kleber Castelano

In this letter, we have considered an electron in a coupled quantum dot system interacting with a detector represented by a point contact. We present a dynamical model for wave function collapse in the strong coupling to the detector limit.…

Mesoscale and Nanoscale Physics · Physics 2017-11-23 H. Cruz