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Related papers: Decoherence in Nearly-Isolated Quantum Dots

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We show that the zero-point fluctuations of the intrinsic electromagnetic environment limit the phase coherence time in all mesoscopic systems at low temperatures. We derive this quantum noise limited dephasing time and its temperature…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 P. Mohanty , R. A. Webb

We investigate the influence of spontaneous symmetry breaking on the decoherence of a many-particle quantum system. This decoherence process is analyzed in an exactly solvable model system that is known to be representative of symmetry…

Strongly Correlated Electrons · Physics 2009-11-10 Jasper van Wezel , Jeroen van den Brink , Jan Zaanen

We investigate shot noise of photon-excited electron-hole pairs in open multi-terminal, multi-channel chaotic dots. Coulomb interactions in the dot are treated self-consistently giving a gauge-invariant expression for the finite frequency…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. L. Polianski , P. Samuelsson , M. Buttiker

We extract the phase coherence of a qubit defined by singlet and triplet electronic states in a gated GaAs triple quantum dot, measuring on timescales much shorter than the decorrelation time of the environmental noise. In this non-ergodic…

Mesoscale and Nanoscale Physics · Physics 2016-01-28 M. R. Delbecq , T. Nakajima , P. Stano , T. Otsuka , S. Amaha , J. Yoneda , K. Takeda , G. Allison , A. Ludwig , A. D. Wieck , S. Tarucha

We study the transmission phase shift across a Kondo correlated quantum dot in a GaAs heterostructure at temperatures below the Kondo temperature ($T < T_{\rm K}$), where the phase shift is expected to show a plateau at $\pi/2$ for an ideal…

Mesoscale and Nanoscale Physics · Physics 2016-08-23 S. Takada , M. Yamamoto , C. Bäuerle , A. Alex , J. von Delft , A. Ludwig , A. D. Wieck , S. Tarucha

We consider decay of an initial density or current perturbation at finite temperature $T$ near a quantum critical point with emergent Lorentz invariance. We argue that decay of perturbations with wavenumbers $k \gg T$ (in natural units) is…

High Energy Physics - Theory · Physics 2020-07-22 Sergei Khlebnikov

We study quantum coherence in a semiconductor charge qubit formed from a GaAs double quantum dot containing a single electron. Voltage pulses are applied to depletion gates to drive qubit rotations and non-invasive state readout is achieved…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 K. D. Petersson , J. R. Petta , H. Lu , A. C. Gossard

The search for quantum coherence based on isolated atoms integrated with a room temperature solid state device (so-called atomchip [1-3]) has been intensifying in the last decade, with advances being made towards applications such as…

Quantum Physics · Physics 2015-02-06 Shuyu Zhou , David Groswasser , Mark Keil , Yonathan Japha , Ron Folman

We calculate the dephasing rate of an electron state in a pinched quantum dot, due to Coulomb interactions between the electron in the dot and electrons in a nearby voltage biased ballistic nanostructure. The dephasing is caused by…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Y. Levinson

For Coulomb blockade peaks in the linear conductance of a quantum dot, we study the correction to the spacing between the peaks due to dot-lead coupling. This coupling can affect measurements in which Coulomb blockade phenomena are used as…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Serguei Vorojtsov , Harold U. Baranger

We study the conductance statistical features of ballistic electrons flowing through a chaotic quantum dot. We show how the temperature affects the universal conductance fluctuations by analyzing the influence of dephasing and thermal…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 E. R. P. Alves , C. H. Lewenkopf

The electrostatic energy of an additional electron on a conducting grain blocks the flow of current through the grain, an effect known as the Coulomb blockade. Current can flow only if two charge states of the grain have the same energy; in…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 E. E. Narimanov , N. R. Cerruti , H. U. Baranger , S. Tomsovic

Coulomb blockade (CB) in a quantum dot (QD) with one anomalously broad level is considered. In this case many consecutive pronounced CB peaks correspond to occupation of one and the same broad level. Between the peaks the electron jumps…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. G. Silvestrov , Y. Imry

It is commonly stated that decoherence in open quantum systems is due to growing entanglement with an environment. In practice, however, surprisingly often decoherence may equally well be described by random unitary dynamics without…

Quantum Physics · Physics 2009-10-29 Julius Helm , Walter T. Strunz

We calculate the Coulomb Blockade peak spacing distribution at finite temperature using the recently introduced ``universal Hamiltonian'' to describe the e-e interactions. We show that the temperature effect is important even at…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Gonzalo Usaj , Harold U. Baranger

We study measures of decoherence and thermalization of a quantum system $S$ in the presence of a quantum environment (bath) $E$. The whole system is prepared in a canonical thermal state at a finite temperature. Applying perturbation theory…

Statistical Mechanics · Physics 2016-03-23 M. A. Novotny , F. Jin , S. Yuan , S. Miyashita , H. De Raedt , K. Michielsen

We investigate decoherence due to pure dephasing of a localized spin qubit interacting with a nuclear spin bath. Although in the limit of a very large magnetic field the only decoherence mechanism is spectral diffusion due to dipolar…

Mesoscale and Nanoscale Physics · Physics 2009-06-18 L. Cywinski , W. M. Witzel , S. Das Sarma

We study the phase of the transmission amplitude through a disordered quantum dot in the Coulomb blockade regime. We calculate the phase dependence on gate voltage for a disorder configuration. We show that over a ``period'', consisting of…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Reinhard Baltin , Yuval Gefen

We study the effective parameters of QED near decoupling temperatures and show that the QED perturbative series is convergent, at temperatures below the decoupling temperature. The renormalization constant of QED acquires different values…

High Energy Physics - Theory · Physics 2017-04-26 Samina S. Masood

We discuss a fundamental effect of the interaction-induced decoherence of the electron wave function in disordered metals. In the first part of the paper we consider a simple model of a quantum particle interacting with a bath of harmonic…

Condensed Matter · Physics 2009-10-31 D. S. Golubev , A. D. Zaikin