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Related papers: Coherence and Screening in Multi-Electron Spin Qub…

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We analytically solve the {\it Non-Markovian} single electron spin dynamics due to hyperfine interaction with surrounding nuclei in a quantum dot. We use the equation-of-motion method assisted with a large field expansion, and find that…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Changxue Deng , Xuedong Hu

We study nonequilibrium dephasing in an electronic Mach-Zehnder interferometer. We demonstrate that the shot noise at the beam splitter of the interferometer generates an ensemble of nonequilibrium electron density configurations and that…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Seok-Chan Youn , Hyun-Woo Lee , H. -S. Sim

It has been proposed that a quantum computer can be constructed based on electron spins in quantum dots or based on a superconducting nanocircuit. During two-qubit operations, the fluctuation of the coupling parameters is a critical factor.…

Materials Science · Physics 2009-11-10 Toshifumi Itakura

Entangling two quantum bits by letting them interact is the crucial requirements for building a quantum processor. For qubits based on the spin of the electron, these two-qubit gates are typically performed by exchange interaction of the…

Mesoscale and Nanoscale Physics · Physics 2015-12-07 Fabian Hassler , Gianluigi Catelani , Hendrik Bluhm

Recent experiments by F. Yoshihara et al. [Phys. Rev. Lett. 97, 167001 (2006)] and by K. Kakuyanagi et al. (cond-mat/0609564) provided information on decoherence of the echo signal in Josephson-junction flux qubits at various bias…

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

Extracting information from quantum many-body systems remains a key challenge in quantum technologies due to experimental limitations. In this work, we employ a single spin qubit to probe a strongly interacting system, creating an…

We present a new model for the study of spin-orbit coupling in interacting quasi-one-dimensional systems and solve it exactly to find the spectral properties of such systems. We show that the combination of spin-orbit coupling and…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. V. Moroz , K. V. Samokhin , C. H. W. Barnes

Resonant exchange qubits are a promising addition to the family of experimentally implemented encodings of single qubits using semiconductor quantum dots. We have shown previously that it ought to be straightforward to perform a CPHASE gate…

Mesoscale and Nanoscale Physics · Physics 2016-03-02 Matthew P. Wardrop , Andrew C. Doherty

This Technical Review collects values of selected performance characteristics of semiconductor spin qubits defined in electrically controlled nanostructures. The characteristics are envisioned to serve as a community source for the values…

Mesoscale and Nanoscale Physics · Physics 2025-03-25 Peter Stano , Daniel Loss

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

The transport of quantum information between different nodes of a quantum device is among the challenging functionalities of a quantum processor. In the context of spin qubits, this requirement can be met by coherent electron spin shuttling…

Mesoscale and Nanoscale Physics · Physics 2024-11-28 Florian Ginzel , Adam R. Mills , Jason R. Petta , Guido Burkard

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

Superconducting circuits are a leading platform for quantum computing. However, their coherence times are still limited and exhibit temporal fluctuations. Those phenomena are often attributed to the coupling between qubits and material…

Quantum Physics · Physics 2022-10-13 Xinyuan You , Ziwen Huang , Ugur Alyanak , Alexander Romanenko , Anna Grassellino , Shaojiang Zhu

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

Motivated by recent experiments with Josephson-junction circuits, we analyze the influence of various noise sources on the dynamics of two-level systems at optimal operation points where the linear coupling to low-frequency fluctuations is…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yuriy Makhlin , Alexander Shnirman

A single electron floating on the surface of a condensed noble-gas liquid or solid can act as a spin qubit with ultralong coherence time, thanks to the extraordinary purity of such systems. Previous studies suggest that the electron spin…

Mesoscale and Nanoscale Physics · Physics 2022-08-05 Qianfan Chen , Ivar Martin , Liang Jiang , Dafei Jin

Spin qubits are very valuable and scalable candidates in the area of quantum computation and simulation applications. In the last decades, they have been deeply investigated from a theoretical point of view and realized on the scale of few…

Quantum Physics · Physics 2019-11-14 E. Ferraro , M. De Michielis

Significant advances have been made towards fault-tolerant operation of silicon spin qubits, with single qubit fidelities exceeding 99.9%, several demonstrations of two-qubit gates based on exchange coupling, and the achievement of coherent…

Mesoscale and Nanoscale Physics · Physics 2019-03-15 A. R. Mills , D. M. Zajac , M. J. Gullans , F. J. Schupp , T. M. Hazard , J. R. Petta

Decoherence of Josephson qubits can be substantially reduced by tuning their parameters to optimal operation points, with only quadratic coupling to fluctuations. We analyze dephasing due to 1/f noise for a two-level system, detuned from an…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. V. Syzranov , Yu. Makhlin

Recent work on Ising-coupled double-quantum-dot spin qubits in GaAs with voltage-controlled exchange interaction has shown improved two-qubit gate fidelities from the application of oscillating exchange along with a strong magnetic field…

Mesoscale and Nanoscale Physics · Physics 2019-02-06 R. K. L. Colmenar , J. P. Kestner