• 文献标题:   Fast spin initialization of a quantum dot in the Voigt configuration coupled to a graphene layer
  • 文献类型:   Article
  • 作  者:   STEFANATOS D, KARANIKOLAS V, ILIOPOULOS N, PASPALAKIS E
  • 作者关键词:   quantum dot, spin initialization, voigt geometry, optical pumping, optimal control, spin dynamic
  • 出版物名称:   PHYSICA ELOWDIMENSIONAL SYSTEMS NANOSTRUCTURES
  • ISSN:   1386-9477 EI 1873-1759
  • 通讯作者地址:   Univ Patras
  • 被引频次:   3
  • DOI:   10.1016/j.physe.2019.113810
  • 出版年:   2020

▎ 摘  要

We study the problem of fast spin initialization for a quantum dot in the Voigt geometry by placing it near a graphene layer. We calculate the spontaneous emission rates of the quantum dot modified by a graphene layer and show that high levels of fidelity, significantly larger than in the case of the quantum dot in free-space, can be quickly obtained due to the anisotropy of the enhanced spontaneous decay rates of the quantum dot near the graphene layer. We use a continuous wave optical field and find the control amplitude which achieves acceptable fidelity levels in short times for different distances of the quantum dot from the graphene layer and for different graphene's chemical potentials. We also use state of the art numerical optimal control to find the time-dependent electric field which maximizes the final fidelity for the same short duration as in the previous case. A better fidelity is obtained with this method, while the resulting pulse is quite robust to positioning error of the quantum dot and to additive constant control error.