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The dynamics of charge qubit in double quantum dot coupled to phonons is investigated theoretically. The static bias is considered. By means of the perturbation approach based on unitary transformations, the dynamical tunneling current is…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Xiufeng Cao , Hang Zheng

We investigate transient dynamic response of an Anderson impurity quantum dot to a family of ramp-up driving voltage applied to the single coupling lead. Transient current is calculated based on a hierarchical equations of motion formalism…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Xiao Zheng , Jinshuang Jin , YiJing Yan

Resonant tunneling through identical potential barriers is a textbook problem in quantum mechanics. Its solution yields total transparency (100% tunneling) at discrete energies. This dramatic phenomenon results from coherent interference…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Daniel Rohrlich , Oren Zarchin , Moty Heiblum , Diana Mahalu , Vladimir Umansky

We examine the Breit-Wigner resonances that ensue from field effects in molecular single electron transistors (SETs). The adiabatic dynamics of a quantum dot elastically attached to electrodes are treated in the Born-Oppenheimer approach.…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 Alexander M. Dykhne , Alexander G. Rudavets

The resonant quantum dynamics of an excited two-level emitter is investigated via classical modulation of its transition frequency while simultaneously the radiator interacts with a broadband electromagnetic field reservoir. The frequency…

Quantum Physics · Physics 2015-06-23 Mihai Macovei , Christoph H. Keitel

We theoretically consider charge transport through two quantum dots coupled in series. The corresponding full counting statistics for noninteracting electrons is investigated in the limits of sequential and coherent tunneling by means of a…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 G. Kiesslich , P. Samuelsson , A. Wacker , E. Schoell

We theoretically study a charge qubit interacting with electrons in a semi-infinite 1D wire. The system displays the physics of the Fermi edge singularity. Our results generalize known results for the Fermi-edge system to the regime where…

Strongly Correlated Electrons · Physics 2013-02-25 A. Sheikhan , I. Snyman

We carry out a detailed analysis of coherent resonant tunneling through two coupled quantum dots (CQD) in a parallel arrangement in the weak tunneling limit. We establish a set of quantum rate equations (QREs) in terms of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Bing Dong , X. L. Lei , N. J. M. Horing

As basic elements of the quantum computer - quantum bits (qubits) we offer semiconductor quantum dots containing one electron each and consisting each of two tunnel-connected parts. The numerical solution of a Schroedinger equation with the…

Quantum Physics · Physics 2007-05-23 L. Fedichkin , M. Yanchenko , K. A. Valiev

We present the conditional quantum dynamics of an electron tunneling between two quantum dots subject to a measurement using a low transparency point contact or tunnel junction. The double dot system forms a single qubit and the measurement…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Hsi-Sheng Goan , Gerard J. Milburn

We investigate Aharonov-Bohm oscillations of the current through a strongly correlated quantum dot embedded in an arbitrary scattering geometry. Resonant-tunneling processes lead to a flux-dependent renormalization of the dot level. As a…

Condensed Matter · Physics 2009-10-28 C. Bruder , Rosario Fazio , Herbert Schoeller

We present microwave frequency measurements of the dynamic admittance of a quantum dot tunnel coupled to a two-dimensional electron gas. The measurements are made via a high-quality 6.75 GHz on-chip resonator capacitively coupled to the…

Mesoscale and Nanoscale Physics · Physics 2012-10-04 T. Frey , P. J. Leek , M. Beck , J. Faist , A. Wallraff , K. Ensslin , T. Ihn , M. Büttiker

We make a thorough study of the spreading of quantum coherence (QC), as quantified by the $l_{1}$-norm QC, when a qubit (a two-level quantum system) is subjected to noise quantum channels commonly appearing in quantum information science.…

Quantum Physics · Physics 2017-02-10 Mauro B. Pozzobom , Jonas Maziero

We consider a model of electrons at zero temperature, with a repulsive interaction which is a function of the energy transfer. Such an interaction can arise from the combination of electron-electron repulsion at high energies and the weaker…

Superconductivity · Physics 2022-06-15 Dimitri Pimenov , Andrey V. Chubukov

In this paper, we carry out a theoretical analysis of the zero-frequency and finite-frequency shot noise in electron tunneling through a two-level interacting system connected to two leads, when a coherent coupling between the two levels is…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Ivana Djuric , Bing Dong , H. L. Cui

We study numerically the behavior of qubit coupled to a quantum dissipative driven oscillator (resonator). Above a critical coupling strength the qubit rotations become synchronized with the oscillator phase. In the synchronized regime, at…

Superconductivity · Physics 2008-01-10 O. V. Zhirov , D. L. Shepelyansky

We have used the mechanical motion of a carbon nanotube (CNT) as a probe of the average charge on a quantum dot. Variations of the resonance frequency and the quality factor are determined by the change in average charge on the quantum dot…

We present a theoretical analysis of the quantum dynamics of a superconducting circuit based on a highly asymmetric Cooper pair transistor (ACPT) in parallel to a dc-SQUID. Starting from the full Hamiltonian we show that the circuit can be…

Mesoscale and Nanoscale Physics · Physics 2010-11-30 A. Fay , W. Guichard , O. Buisson , F. W. J. Hekking

Resonant tunneling in an open mesoscopic quantum dot is proposed as a vehicle to realize a tunable Fermi-edge resonance with variable coupling strength. We solve the x-ray edge problem for a generic nonseparable scatterer and apply it to…

Mesoscale and Nanoscale Physics · Physics 2008-04-12 D. A. Abanin , L. S. Levitov

A new regime of coherent quantum dynamics of a qubit is realized at low driving frequencies in the strong driving limit. Coherent transitions between qubit states occur via the Landau-Zener process when the system is swept through an…