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DOE OSTI · 22038612

Optimal primitive reference frames

Jennings, David
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Abstract

We consider the smallest possible directional reference frames allowed and determine the best one can ever do in preserving quantum information in various scenarios. We find that for the preservation of a single spin state, two orthogonal spins are optimal primitive reference frames; and in a product state, they do approximately 22% as well as an infinite-sized classical frame. By adding a small amount of entanglement to the reference frame, this can be raised to 2(2/3){sup 5}=26%. Under the different criterion of entanglement preservation, a very similar optimal reference frame is found; however, this time it is for spins aligned at an optimal angle of 87 deg. In this case 24% of the negativity is preserved. The classical limit is considered numerically, and indicates under the criterion of entanglement preservation, that 90 deg. is selected out nonmonotonically, with a peak optimal angle of 96.5 deg. for L=3 spins.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICSQUANTUM ENTANGLEMENTQUANTUM INFORMATIONQUANTUM STATESSPIN

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Jennings, David. 2011-07-15. Optimal primitive reference frames. https://doi.org/10.1103/physreva.84.012306

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