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Related papers: Decoherence of an exchange qubit by hyperfine inte…

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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 propose a mechanism of long-range coherent coupling between nuclear spins to be used as qubits in solid-state semiconductor-heterojunction quantum information processing devices. The coupling is via localized donor electrons which in…

Mesoscale and Nanoscale Physics · Physics 2010-09-22 Dima Mozyrsky , Vladimir Privman , M. Lawrence Glasser

Relaxation and dephasing of hole spins are measured in a gate-defined Ge/Si nanowire double quantum dot using a fast pulsed-gate method and dispersive readout. An inhomogeneous dephasing time $T_2^* \sim 0.18~\mathrm{\mu s}$ exceeds…

Mesoscale and Nanoscale Physics · Physics 2014-06-16 A. P. Higginbotham , T. W. Larsen , J. Yao , H. Yan , C. M. Lieber , C. M. Marcus , F. Kuemmeth

We derive an accurate molecular orbital based expression for the coherent time evolution of a two-electron wave function in a quantum dot molecule where the electrons interact with each other, with external time dependent electromagnetic…

Other Condensed Matter · Physics 2009-11-13 R. Nepstad , L. Sælen , J. P. Hansen

Quantum dots are arguably the best interface between matter spin qubits and flying photonic qubits. Using quantum dot devices to produce joint spin-photonic states requires the electronic spin qubits to be stored for extended times.…

We measure the strength and the sign of hyperfine interaction of a heavy-hole with nuclear spins in single self-assembled quantum dots. Our experiments utilize the locking of a quantum dot resonance to an incident laser frequency to…

Mesoscale and Nanoscale Physics · Physics 2010-09-02 P. Fallahi , S. T. Yilmaz , A. Imamoglu

The goal of this article is to review the progress of three-electron spin qubits from their inception to the state of the art. We direct the main focus towards the resonant exchange (RX) qubit and the exchange-only qubit, but we also…

Mesoscale and Nanoscale Physics · Physics 2017-09-14 Maximilian Russ , Guido Burkard

We study the scaling of decoherence of decoupled electron spin qubits due to hyperfine interaction. For a superposed state consisting of product states from a single Zeeman manifold, both $T_2^*(n)$ and $T_2(n)$ are scale-free with respect…

Quantum Physics · Physics 2015-03-02 Jun Jing , Xuedong Hu

We theoretically consider coherence times for spins in two quantum computer architectures, where the qubit is the spin of an electron bound to a P donor impurity in Si or within a GaAs quantum dot. We show that low temperature decoherence…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Rogerio de Sousa , S. Das Sarma

Spin qubits in semiconductor quantum dots are one of the promizing devices to realize a quantum processor. A better knowledge of the noise sources affecting the coherence of such a qubit is therefore of prime importance. In this work, we…

Mesoscale and Nanoscale Physics · Physics 2023-04-04 Baker Shalak , Christophe Delerue , Yann-Michel Niquet

We revisit the problem of decoherence of a qubit centrally coupled to an interacting spin environment, here modeled by a quantum compass chain or an extended XY model in a staggered magnetic field. These two models both support distinct…

Statistical Mechanics · Physics 2017-12-22 R. Jafari , Henrik Johannesson

Fluctuations of electric fields can change the position of a gate-defined quantum dot in a semiconductor heterostructure. In the presence of magnetic field gradient, these stochastic shifts of electron's wavefunction lead to fluctuations of…

Mesoscale and Nanoscale Physics · Physics 2024-08-09 Marcin Kępa , Łukasz Cywiński , Jan A. Krzywda

Future communication and computation technologies that exploit quantum information require robust and well-isolated qubits. Electron spins in III-V semiconductor quantum dots, while promising candidates, see their dynamics limited by…

Decoherence in quantum logic gates (qubits) due to interaction with the surrounding environment is a major obstacle to the practical realization of quantum information technologies. For solid state electron-spin qubits the interaction with…

Mesoscale and Nanoscale Physics · Physics 2015-02-24 E. A. Chekhovich , M. Hopkinson , M. S. Skolnick , A. I. Tartakovskii

The spin of an electron trapped in a quantum dot is a promising candidate implementation of a qubit for quantum information processing. We study the central spin problem of the effect of the hyperfine interaction between such an electron…

Mesoscale and Nanoscale Physics · Physics 2007-08-29 Gang Chen , Doron L. Bergman , Leon Balents

Understanding the spin dephasing mechanism is of fundamental importance in all potential applications of the spin qubit. Here we demonstrate a spin dephasing mechanism in semiconductor quantum dot due to the $1/f$ charge noise. The…

Mesoscale and Nanoscale Physics · Physics 2018-09-12 Rui Li

We investigate in detail, using both analytical and numerical tools, the decoherence of electron spins in quantum dots (QDs) coupled to a bath of nuclear spins in magnetic fields or with various initial bath polarizations, focusing on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Wenxian Zhang , V. V. Dobrovitski , K. A. Al-Hassanieh , E. Dagotto , B. N. Harmon

We study Si:P donor electron spin decoherence due to anisotropic hyperfine (AHF) interaction with the surrounding nuclear spin bath. In particular, we clarify the electron spin echo envelope modulation (ESEEM) in the Si:P system and the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 W. M. Witzel , Xuedong Hu , S. Das Sarma

We theoretically investigate the spin dynamics of a heavy hole confined to an unstrained III-V semiconductor quantum dot and interacting with a narrowed nuclear-spin bath. We show that band hybridization leads to an exponential decay of…

Mesoscale and Nanoscale Physics · Physics 2010-12-27 Jan Fischer , Daniel Loss

One of the key pathways towards scalability of spin-based quantum computing systems lies in achieving long-range interactions between electrons and increasing their inter-connectivity. Coherent spin transport is one of the most promising…