Relaxation and Readout Visibility of a Singlet-Triplet Qubit in an Overhauser Field Gradient

C. Barthel; J. Medford; H. Bluhm; A. Yacoby; C. M. Marcus; M. P. Hanson; A. C. Gossard

doi:10.1103/PhysRevB.85.035306

Relaxation and Readout Visibility of a Singlet-Triplet Qubit in an Overhauser Field Gradient

Mesoscale and Nanoscale Physics 2012-07-12 v1 Quantum Physics

Authors: C. Barthel , J. Medford , H. Bluhm , A. Yacoby , C. M. Marcus , M. P. Hanson , A. C. Gossard

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Abstract

Using single-shot charge detection in a GaAs double quantum dot, we investigate spin relaxation time T_1 and readout visibility of a two-electron singlet-triplet qubit following single-electron dynamic nuclear polarization (DNP). For magnetic fields up to 2 T, the DNP cycle is in all cases found to increase Overhauser field gradients, which in turn decrease T_1 and consequently reduce readout visibility. This effect was previously attributed to a suppression of singlet-triplet dephasing under a similar DNP cycle. A model describing relaxation after singlet-triplet mixing agrees well with experiment. Effects of pulse bandwidth on visibility are also investigated.

Keywords

singlet-triplet qubit Overhauser field gradient dynamic nuclear polarization spin relaxation time readout visibility GaAs double quantum dot single-shot charge detection

Cite

@article{arxiv.1108.4210,
  title  = {Relaxation and Readout Visibility of a Singlet-Triplet Qubit in an Overhauser Field Gradient},
  author = {C. Barthel and J. Medford and H. Bluhm and A. Yacoby and C. M. Marcus and M. P. Hanson and A. C. Gossard},
  journal= {arXiv preprint arXiv:1108.4210},
  year   = {2012}
}

Relaxation and Readout Visibility of a Singlet-Triplet Qubit in an Overhauser Field Gradient

Abstract

Keywords

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