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arXiv · 1906.02378

Charge noise induced spin dephasing in a nanowire double quantum dot with spin-orbit coupling

Rui Li
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Abstract

Unexpected fluctuating charge field near a semiconductor quantum dot has severely limited the coherence time of the localized spin qubit. It is the interplay between the spin-orbit coupling and the asymmetrical confining potential in a quantum dot, that mediates the longitudinal interaction between the spin qubit and the fluctuating charge field. Here, we study the $1/f$ charge noise induced spin dephasing in a nanowire double quantum dot via exactly solving its eigen-energies and eigenfunctions. Our calculations demonstrate that the spin dephasing has a nonmonotonic dependence on the asymmetry of the double quantum dot confining potential. With the increase of the potential asymmetry, the dephasing rate first becomes stronger very sharply before reaching to a maximum, after that it becomes weaker softly. Also, we find that the applied external magnetic field contributes to the spin dephasing, the dephasing rate is strongest at the anti-crossing point $B_{0}$ in the double quantum dot.

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Rui Li. 2019-06-06. Charge noise induced spin dephasing in a nanowire double quantum dot with spin-orbit coupling. https://doi.org/10.1088/1361-648x/ab4933

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