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Related papers: Decoherence of a Driven Qubit

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The spin of an electron in a semiconductor quantum dot represents a natural nanoscale solid state qubit. Coupling to nuclear spins leads to decoherence that limits the number of allowed quantum logic operations for this qubit. Traditional…

Mesoscale and Nanoscale Physics · Physics 2016-07-13 Alexander Bechtold , Fuxiang Li , Kai Müller , Tobias Simmet , Per-Lennart Ardelt , Jonathan J. Finley , Nikolai A. Sinitsyn

We demonstrate that an optically driven spin of a carrier in a quantum dot undergoes indirect dephasing via conditional optically induced charge evolution even in the absence of any direct interaction between the spin and its environment. A…

Mesoscale and Nanoscale Physics · Physics 2009-04-27 A. Grodecka , P. Machnikowski , J. Förstner

For many implementations of quantum computing, 1/f and other types of broad-spectrum noise are an important source of decoherence. An important step forward would be the ability to back out the characteristics of this noise from qubit…

Quantum Physics · Physics 2013-05-29 Dong Zhou , Robert Joynt

We consider a mechanism of spin decay for an electron spin in a quantum dot due to coupling to a nearby quantum point contact (QPC) with and without an applied bias voltage. The coupling of spin to charge is induced by the spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Massoud Borhani , Vitaly N. Golovach , Daniel Loss

The loss of coherence is one of the main obstacles for the implementation of quantum information processing. The efficiency of dynamical decoupling schemes, which have been introduced to address this problem, is limited itself by the…

Molecular spins offer promise in emerging quantum technologies such as quantum sensing and computing. At low temperatures, nuclear spin-spin interactions affect electron spin coherence lifetimes through pure dephasing. Nuclear-spin noise…

Quantum Physics · Physics 2026-05-06 Timothy J. Krogmeier , James Bradley , Anthony W. Schlimgen , Kade Head-Marsden

A high degree of quantum coherence is a crucial requirement for the implementation of quantum logic devices. Solid state nanodevices seem particularly promising from the point of view of integrability and flexibility in the design. However…

Superconductivity · Physics 2007-05-23 G. Falci , E. Paladino , R. Fazio

We measure the dependence of qubit phase coherence and surface spin induced flux noise on inductor loop geometry. While wider inductor traces change neither the flux noise power spectrum nor the qubit dephasing time, increased inductance…

The dynamics of a spin in the presence of a deterministic and a fluctuating magnetic field is solved for analytically to obtain the averaged value of the spin as a function of time for various kinds of fluctuations (noise). Specifically,…

Mesoscale and Nanoscale Physics · Physics 2014-03-21 Piotr Szańkowski , M. Trippenbach , Y. B. Band

We study electron-phonon interaction induced decoherence between two-electron singlet and triplet states in a semiconductor double quantum dot using a spin-boson model. We investigate the onset and time evolution of this dephasing, and…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Xuedong Hu

We study decoherence effects in qubits coupled to environments that exhibit resonant frequencies in their spectral function. We model the coupling of the qubit to its environment via the Caldeira-Leggett formulation of quantum…

Superconductivity · Physics 2010-06-07 Kaushik Mitra , C. A. R. Sá de Melo

In this report, we examine the decoherence of a spin qubits system coupled to counted spin chain with a $1/r^2$ interaction by using influence functional. We also examine the time evolution of density matrix numerically when environment is…

Mesoscale and Nanoscale Physics · Physics 2008-12-20 Toshifumi Itakura

Quantum coherence of superposed states, especially of entangled states, is indispensable for many quantum technologies. However, it is vulnerable to environmental noises, posing a fundamental challenge in solid-state systems including spin…

We present a general and exact formalism for finding the evolution of a quantum system subject to external telegraph noise. The various qubit decoherence rates are determined by the eigenvalues of a transfer matrix. The formalism can be…

Quantum Physics · Physics 2009-11-13 Bin Cheng , Qiang-Hua Wang , Robert Joynt

The qubit (or a system of two quantum dots) has become a standard paradigm for studying quantum information processes. Our focus is Decoherence due to interaction of the qubit with its environment, leading to noise. We consider quantum…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Ebad Kamil , Sushanta Dattagupta

The decoherence of a qubit due to a classical non-Gaussian noise with correlation time longer than the decoherence time is discussed for arbitrary working points of the qubit. A method is developed that allows an exact formula for the phase…

Superconductivity · Physics 2009-11-11 J. Bergli , Y. M. Galperin , B. L. Altshuler

Entangled qubits transported through space is a key element in many prospective quantum information systems, from long-distance quantum communication to large modular quantum processors. The moving qubits are decohered by time- and…

Mesoscale and Nanoscale Physics · Physics 2024-09-09 Aleksandr S. Mokeev , Yu-Ning Zhang , Viatcheslav V. Dobrovitski

By investigating the evolution of a moving spin-1/2 Dirac electron coupled with a background magnetic noise, we demonstrate that the effects of special relativity will significantly modify the decoherence properties of the spin state. The…

Quantum Physics · Physics 2007-10-03 Jian-Ming Cai , Zheng-Wei Zhou , Ye-Fei Yuan , Guang-Can Guo

Random fluctuations caused by environmental noise can lead to decoherence in quantum systems. Exploring and controlling such dissipative processes is both fundamentally intriguing and essential for harnessing quantum systems to gain…

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