| Autor: |
Guichard, R., Balian, S. J., Wolfowicz, G., Mortemousque, P. A., Monteiro, T. S. |
| Rok vydání: |
2014 |
| Předmět: |
|
| Zdroj: |
Phys. Rev. B 91, 214303 (2015) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.91.214303 |
| Popis: |
Hybrid qubit systems combining electronic spins with nearby ("proximate") nuclear spin registers offer a promising avenue towards quantum information processing, with even multi-spin error correction protocols recently demonstrated in diamond. However, for the important platform offered by spins of donor atoms in cryogenically-cooled silicon,decoherence mechanisms of $^{29}$Si proximate nuclear spins are not yet well understood.The reason is partly because proximate spins lie within a so-called "frozen core" region where the donor electronic hyperfine interaction strongly suppresses nuclear dynamics. We investigate the decoherence of a central proximate nuclear qubit arising from quantum spin baths outside, as well as inside, the frozen core around the donor electron. We consider the effect of a very large nuclear spin bath comprising many ($\gtrsim 10^8$) weakly contributing pairs outside the frozen core. We also propose that there may be an important contribution from a few (of order $100$) symmetrically sited nuclear spin pairs ("equivalent pairs"), which were not previously considered as their effect is negligible outside the frozen core. If equivalent pairs represent a measurable source of decoherence, nuclear coherence decays could provide sensitive probes of the symmetries of electronic wavefunctions. For the phosphorus donor system, we obtain $T_{2n}$ values of order 1 second for both the "far bath" and "equivalent pair" models, confirming the suitability of proximate nuclei in silicon as very long-lived spin qubits. |
| Databáze: |
arXiv |
| Externí odkaz: |
|
