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The Quantum Speed Limit of Optimal Controlled Phasegates for Trapped Neutral Atoms

Quantum Physics 2011-07-27 v1

Abstract

We study controlled phasegates for ultracold atoms in an optical potential. A shaped laser pulse drives transitions between the ground and electronically excited states where the atoms are subject to a long-range 1/R^3 interaction. We fully account for this interaction and use optimal control theory to calculate the pulse shapes. This allows us to determine the minimum pulse duration, respectively, gate time T that is required to obtain high fidelity. We accurately analyze the speed limiting factors, and we find the gate time to be limited either by the interaction strength in the excited state or by the ground state vibrational motion in the trap. The latter needs to be resolved by the pulses in order to fully restore the motional state of the atoms at the end of the gate.

Keywords

Cite

@article{arxiv.1103.6050,
  title  = {The Quantum Speed Limit of Optimal Controlled Phasegates for Trapped Neutral Atoms},
  author = {Michael H. Goerz and Tommaso Calarco and Christiane P. Koch},
  journal= {arXiv preprint arXiv:1103.6050},
  year   = {2011}
}

Comments

11 pages, 10 figures, 1 table