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We investigate the charge-detection-induced dephasing of a charge qubit interacting with an electronic beam collider composed of a quantum point contact. We report that, while the qubit is dephased by the partitioned beam of uncorrelated…

Mesoscale and Nanoscale Physics · Physics 2007-10-02 Youngnae Lee , Gyong Luck Khym , Kicheon Kang

Solid-state systems which mimic two-level atoms are being actively developed. Improving the quantum coherence of these systems, for instance spin qubits or single photon emitters using semiconductor quantum dots, involves dealing with…

In this paper we study the low temperature kinetics of the electrons in the system composed of a quantum dot connected to two leads by solving the equation of motion. The decoherence and the relaxation of the system caused by the gate…

Strongly Correlated Electrons · Physics 2009-11-13 M. Q. Weng

We investigate how decoherence affects the entanglement established between two quantum dots in micro cavities, and propose a tomographic scheme able to measure the entangled state. The scheme we consider establishes the entanglement via…

Quantum Physics · Physics 2013-07-30 Asier Pineiro-Orioli , Dara P. S. McCutcheon , Terry Rudolph

Charge qubits formed in double quantum dots represent quintessential two-level systems that enjoy both ease of control and efficient readout. Unfortunately, charge noise can cause rapid decoherence, with typical single-qubit gate fidelities…

Mesoscale and Nanoscale Physics · Physics 2019-03-11 Yuan-Chi Yang , S. N. Coppersmith , Mark Friesen

We study non-perturbatively the time evolution of a qubit subject to amplitude-damping noise. We show that at strong coupling the qubit decoherence can be quenched owing to large environment feedbacks, such that the qubit can evolve…

Quantum Physics · Physics 2014-03-11 Shin-Tza Wu

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…

The dynamics of charge qubit in a double quantum dot coupled to phonons is investigated theoretically in terms of a perturbation treatment based on a unitary transformation. The dynamical tunneling current is obtained explicitly. The result…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Zhuo-Jie Wu , Ka-Di Zhu , Xiao-Zhong Yuan , Yi-Wen Jiang , Hang Zheng

Unexpected fluctuating charge field near a semiconductor quantum dot has severely limited the coherence time of the localized spin qubit. It is the interplay between the spin-orbit coupling and the asymmetrical confining potential in a…

Mesoscale and Nanoscale Physics · Physics 2021-06-29 Rui Li

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

In a 'controlled dephasing' experiment [1-3], an interferometer loses its coherence due to entanglement with a controlled quantum system ('which path' detector). In experiments that were conducted thus far in mesoscopic systems only partial…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 I. Neder , F. Marquardt , M. Heiblum , D. Mahalu , V. Umansky

We show that the intriguing observation of noise enhancement in the charge transport through two vertically coupled quantum dots can be explained by the interplay of quantum coherence and strong Coulomb blockade. We demonstrate that this…

Mesoscale and Nanoscale Physics · Physics 2007-11-18 G. Kiesslich , E. Schoell , T. Brandes , F. Hohls , R. J. Haug

A fundamental question in quantum transport is how quantum coherence influences charge transfer through nanostructures. We address this issue for linear triple quantum dots by comparison of a Lindblad density matrix description with a Pauli…

Mesoscale and Nanoscale Physics · Physics 2017-04-26 L. D. Contreras-Pulido , M. Bruderer

With the growing efforts in isolating solid-state qubits from external decoherence sources, the material-inherent sources of noise start to play crucial role. One representative example is electron traps in the device material or substrate.…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Y. M. Galperin , B. L. Altshuler , D. V. Shantsev

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 review results on evaluation of loss of information in quantum registers due to their interactions with the environment. It is demonstrated that an optimal measure of the level of quantum noise effects can be introduced via the maximal…

Quantum Physics · Physics 2010-09-22 L. Fedichkin , V. Privman

We consider the dephasing of an one-electron state in a quantum dot due to charge fluctuations in a biased quantum point contact coupled to the dot capacitively. The contribution to the dephasing rate due to the bias depends on temperature…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Yehoshua Levinson

It is generally assumed that environmental noise arising from thermal fluctuations is detrimental to preserving coherence and entanglement in a quantum system. In the simplest sense, dephasing and decoherence are tied to energy fluctuations…

Quantum Physics · Physics 2023-08-03 Eric R Bittner , Hao Li , Syad A. Shah , Carlos Silva , Andrei Piryatinski

We propose and discuss two conjectures on the nature of information leaks (decoherence) for quantum computers. These conjectures, if (or when) they hold, are damaging for quantum error-correction as required by fault-tolerant quantum…

Quantum Physics · Physics 2008-06-17 Gil Kalai

Destructive interference of single-electron tunneling between three quantum dots can trap an electron in a coherent superposition of charge on two of the dots. Coupling to external charges causes decoherence of this superposition, and in…

Mesoscale and Nanoscale Physics · Physics 2007-06-13 C. W. Groth , B. Michaelis , C. W. J. Beenakker