English
Related papers

Related papers: Quantum bath-driven decoherence of mixed spin syst…

200 papers

Silicon is promising for spin-based quantum computation because nuclear spins, a source of magnetic noise, may be eliminated through isotopic enrichment. Long spin decoherence times, $T_2$, have been measured in isotope-enriched silicon but…

Mesoscale and Nanoscale Physics · Physics 2010-10-29 Wayne M. Witzel , Malcolm S. Carroll , Andrea Morello , Lukasz Cywinski , S. Das Sarma

Long-range quantum communication for spin qubits is an important open problem. Here we study decoherence of an electron spin qubit that is being transported in a moving quantum dot. We focus on spin decoherence due to spin-orbit interaction…

Mesoscale and Nanoscale Physics · Physics 2013-08-12 Peihao Huang , Xuedong Hu

We investigate the performance of dynamical decoupling methods at suppressing electron spin decoherence from a low-temperature nuclear spin reservoir in a quantum dot. The controlled dynamics is studied through exact numerical simulation,…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Wenxian Zhang , V. V. Dobrovitski , Lea F. Santos , Lorenza Viola , B. N. Harmon

Electron spin qubit coherence in quantum dots is ultimately limited by random nuclear spin bath fluctuations. Here we aim to eliminate this randomness by making spin bath evolution deterministic. We introduce spin bath control sequences,…

Mesoscale and Nanoscale Physics · Physics 2019-07-18 A. M. Waeber , M. Hopkinson , M. S. Skolnick , E. A. Chekhovich

We study the influence of narrowed distributions of the nuclear Overhauser field on the decoherence of a central electron spin in quantum dots. We describe the spin dynamics in quantum dots by the central spin model. We use analytic…

Mesoscale and Nanoscale Physics · Physics 2016-09-16 Lars B. Gravert , Peter Lorenz , Carsten Nase , Joachim Stolze , Götz S. Uhrig

Long coherence times are key to the performance of quantum bits (qubits). Here, we experimentally and theoretically show that the Hahn-echo coherence time (T2) of electron spins associated with divacancy defects in 4H-SiC reaches 1.3 ms,…

Mesoscale and Nanoscale Physics · Physics 2016-10-03 Hosung Seo , Abram L. Falk , Paul V. Klimov , Kevin C. Miao , Giulia Galli , David D. Awschalom

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

We numerically investigate decoherence of a two-spin system (central system) by a bath of many spins 1/2. By carefully adjusting parameters, the dynamical regime of the bath has been varied from quantum chaos to regular, while all other…

Quantum Physics · Physics 2009-11-10 J. Lages , V. V. Dobrovitski , B. N. Harmon

We present a quantum solution to the electron spin decoherence by a nuclear pair-correlation method for the electron-nuclear spin dynamics under a strong magnetic field and a temperature high for the nuclear spins but low for the electron.…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Wang Yao , Ren-Bao Liu , L. J. Sham

In this paper, we investigate the decoherence of qubit due to its coupling to a Hermitian or a non-Hermitian bath within the pure dephasing spin-boson model. First, using this model, we analytically establish the previously anticipated…

Quantum Physics · Physics 2025-12-18 Yue-Hong Wu , Ning-Hua Tong

We consider a SQUID tunneling between 2 nearly degenerate flux states. Decoherence caused by paramagnetic and nuclear spins in the low-$T$ limit is shown to be much stronger than that from electronic excitations. The decoherence time…

Condensed Matter · Physics 2007-05-23 Nikolay Prokof'ev , Philip Stamp

We introduce, and determine decoherence for, a wide class of non-trivial quantum spin baths which embrace Ising, XY and Heisenberg universality classes coupled to a two-level system. For the XY and Ising universality classes we provide an…

We analyze the decoherence dynamics of a central spin coupled to a spin chain with a time-dependent noisy magnetic field, focusing on how noise influences the system's decoherence. Our results show that decoherence due to the nonequilibrium…

Quantum Physics · Physics 2025-05-22 R. Jafari , A. Asadian , M. Abdi , Alireza Akbari

We consider here the problem of a "central spin", with spin quantum number $S \gg 1$, interacting with a set of microscopic spins. Interactions between the microscopic spins are ignored. This model describes magnetic grains or magnetic…

Condensed Matter · Physics 2016-08-31 N. V. Prokof'ev , P. C. E. Stamp

The nitrogen-vacancy (NV) centre, as a promising candidate solid state system of quantum information processing, its electron spin coherence is influenced by the magnetic field fluctuations due to the local environment. In pure diamonds,…

Mesoscale and Nanoscale Physics · Physics 2011-04-08 Nan Zhao , Jian-Liang Hu , Sai-Wah Ho , Tsz-Kai Wen , R. B. Liu

We report an anomalous decoherence phenomenon of a quantum dissipative system in the framework of a stochastic decoupling scheme along with a hierarchical equations-of-motion formalism without the usual Born-Markov or weak coupling…

Quantum Physics · Physics 2016-12-22 Wei Wu , Hai-Qing Lin

We review progress on the spintronics proposal for quantum computing where the quantum bits (qubits) are implemented with electron spins. We calculate the exchange interaction of coupled quantum dots and present experiments, where the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hans-Andreas Engel , L. P. Kouwenhoven , Daniel Loss , C. M. Marcus

A major challenge in using spins in the solid state for quantum technologies is protecting them from sources of decoherence. This can be addressed, to varying degrees, by improving material purity or isotopic composition for example, or…

The nuclear spin of a phosphorus atom in silicon has been used as a quantum bit in various quantum-information experiments. It has been proposed that this nuclear-spin qubit can be efficiently controlled by an ac electric field, when…

Mesoscale and Nanoscale Physics · Physics 2019-10-02 Bence Hetényi , Péter Boross , András Pályi

In this work the problem of characterizing matrix material structure from embedded electron spin decoherence is studied both theoretically and experimentally. Theoretical calculation using nuclear spin bath model and cluster correlation…