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

• Published in: Journal of physics. Condensed matter Vol. 32; no. 2; pp. 25305 - 25313
• Main Author: Li (李 睿), Rui
• Format: Journal Article
• Language: English
• Published: IOP Publishing 09.01.2020
• Subjects: charge noise; quantum dot; spin dephasing; spin-orbit coupling
• ISSN: 0953-8984; 1361-648X; 1361-648X
• DOI: 10.1088/1361-648X/ab4933

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 B0 in the double quantum dot.