Pal, A;
Nichol, JM;
Shulman, MD;
Harvey, SP;
Umansky, V;
Rashba, EI;
Yacoby, A;
(2017)
Electron spin-flip correlations due to nuclear dynamics in driven GaAs double dots.
Physical Review B
, 95
(3)
, Article 035306. 10.1103/physrevb.95.035306.
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Abstract
We present experimental data and associated theory for correlations in a series of experiments involving repeated Landau-Zener sweeps through the crossing point of a singlet state and a spin-aligned triplet state in a GaAs double quantum dot containing two conduction electrons, which are loaded in the singlet state before each sweep, and the final spin is recorded after each sweep. The experiments reported here measure correlations on time scales from 4 μ s to 2 ms. When the magnetic field is aligned in a direction such that spin-orbit coupling cannot cause spin flips, the correlation spectrum has prominent peaks centered at zero frequency and at the differences of the Larmor frequencies of the nuclei, on top of a frequency-independent background. When the spin-orbit field is relevant, there are additional peaks, centered at the frequencies of the individual species. A theoretical model which neglects the effects of high-frequency charge noise correctly predicts the positions of the observed peaks, and gives a reasonably accurate prediction of the size of the frequency-independent background, but gives peak areas that are larger than the observed areas by a factor of 2 or more. The observed peak widths are roughly consistent with predictions based on nuclear dephasing times of the order of 60 μ s . However, there is extra weight at the lowest observed frequencies, which suggests the existence of residual correlations on the scale of 2 ms. We speculate on the source of these discrepancies.
| Type: | Article |
|---|---|
| Title: | Electron spin-flip correlations due to nuclear dynamics in driven GaAs double dots |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1103/physrevb.95.035306 |
| Publisher version: | https://doi.org/10.1103/physrevb.95.035306 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10084471 |
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