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Nuclear spin state narrowing via gate--controlled Rabi oscillations in a double quantum dot

D. Klauser·W. A. Coish·Daniel Loss
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Abstract

We study spin dynamics for two electrons confined to a double quantum dot under the influence of an oscillating exchange interaction. This leads to driven Rabi oscillations between the $\ket{\uparrow\downarrow}$--state and the $\ket{\downarrow\uparrow}$--state of the two--electron system. The width of the Rabi resonance is proportional to the amplitude of the oscillating exchange. A measurement of the Rabi resonance allows one to narrow the distribution of nuclear spin states and thereby to prolong the spin decoherence time. Further, we study decoherence of the two-electron states due to the hyperfine interaction and give requirements on the parameters of the system in order to initialize in the $\ket{\uparrow\downarrow}$--state and to perform a $\sqrt{\mathrm{SWAP}}$ operation with unit fidelity.

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D. Klauser, W. A. Coish, Daniel Loss. 2006-03-13. Nuclear spin state narrowing via gate--controlled Rabi oscillations in a double quantum dot. https://doi.org/10.1103/physrevb.73.205302

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