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Counter-diabatic driving for fast spin control in a two-electron double quantum dot.

Ban Y, Chen X - Sci Rep (2014)

Bottom Line: The techniques of shortcuts to adiabaticity have been proposed to accelerate the "slow" adiabatic processes in various quantum systems with the applications in quantum information processing.In addition, the relation between energy and time is quantified to show the lower bound for the operation time when the maximum amplitude of electric fields is given.Finally, the fidelity is discussed with respect to noise and systematic errors, which demonstrates that the decoherence effect induced by stochastic environment can be avoided in speeded-up adiabatic control.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronic Information Materials, Shanghai University, 200444 Shanghai, People's Republic of China.

ABSTRACT
The techniques of shortcuts to adiabaticity have been proposed to accelerate the "slow" adiabatic processes in various quantum systems with the applications in quantum information processing. In this paper, we study the counter-diabatic driving for fast adiabatic spin manipulation in a two-electron double quantum dot by designing time-dependent electric fields in the presence of spin-orbit coupling. To simplify implementation and find an alternative shortcut, we further transform the Hamiltonian in term of Lie algebra, which allows one to use a single Cartesian component of electric fields. In addition, the relation between energy and time is quantified to show the lower bound for the operation time when the maximum amplitude of electric fields is given. Finally, the fidelity is discussed with respect to noise and systematic errors, which demonstrates that the decoherence effect induced by stochastic environment can be avoided in speeded-up adiabatic control.

No MeSH data available.


Fidelity F versus dephasing rate γ with respect to tf = 2 ns (solid blue line), tf = 3 ns (dashed red line), tf = 4 ns (dot-dashed black line).
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f5: Fidelity F versus dephasing rate γ with respect to tf = 2 ns (solid blue line), tf = 3 ns (dashed red line), tf = 4 ns (dot-dashed black line).

Mentions: For a realistic setup, the coupling to the stochastic environment is a general scenario to be considered, where the hyperfine interactions with the nuclear spin could play important role at low temperature. To study the decoherence effect, we present the master equation for the density matrix36 in a generic form: where γ is the dephasing rate. Solving the Bloch equation, we can obtain the final fidelity (F = ρ11) for different times, see Fig. 5, and demonstrate that the faster manipulation increases the fidelity with less influences attributed by decoherence.


Counter-diabatic driving for fast spin control in a two-electron double quantum dot.

Ban Y, Chen X - Sci Rep (2014)

Fidelity F versus dephasing rate γ with respect to tf = 2 ns (solid blue line), tf = 3 ns (dashed red line), tf = 4 ns (dot-dashed black line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150114&req=5

f5: Fidelity F versus dephasing rate γ with respect to tf = 2 ns (solid blue line), tf = 3 ns (dashed red line), tf = 4 ns (dot-dashed black line).
Mentions: For a realistic setup, the coupling to the stochastic environment is a general scenario to be considered, where the hyperfine interactions with the nuclear spin could play important role at low temperature. To study the decoherence effect, we present the master equation for the density matrix36 in a generic form: where γ is the dephasing rate. Solving the Bloch equation, we can obtain the final fidelity (F = ρ11) for different times, see Fig. 5, and demonstrate that the faster manipulation increases the fidelity with less influences attributed by decoherence.

Bottom Line: The techniques of shortcuts to adiabaticity have been proposed to accelerate the "slow" adiabatic processes in various quantum systems with the applications in quantum information processing.In addition, the relation between energy and time is quantified to show the lower bound for the operation time when the maximum amplitude of electric fields is given.Finally, the fidelity is discussed with respect to noise and systematic errors, which demonstrates that the decoherence effect induced by stochastic environment can be avoided in speeded-up adiabatic control.

View Article: PubMed Central - PubMed

Affiliation: Department of Electronic Information Materials, Shanghai University, 200444 Shanghai, People's Republic of China.

ABSTRACT
The techniques of shortcuts to adiabaticity have been proposed to accelerate the "slow" adiabatic processes in various quantum systems with the applications in quantum information processing. In this paper, we study the counter-diabatic driving for fast adiabatic spin manipulation in a two-electron double quantum dot by designing time-dependent electric fields in the presence of spin-orbit coupling. To simplify implementation and find an alternative shortcut, we further transform the Hamiltonian in term of Lie algebra, which allows one to use a single Cartesian component of electric fields. In addition, the relation between energy and time is quantified to show the lower bound for the operation time when the maximum amplitude of electric fields is given. Finally, the fidelity is discussed with respect to noise and systematic errors, which demonstrates that the decoherence effect induced by stochastic environment can be avoided in speeded-up adiabatic control.

No MeSH data available.