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Minimum-energy pulses for quantum logic cannot be shared

Julio Gea-Banacloche·Masanao Ozawa
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Abstract

We show that if an electromagnetic energy pulse with average photon number is used to carry out the same quantum logical operation on a set of N atoms, either simultaneously or sequentially, the overall error probability in the worst case scenario (i.e., maximized over all the possible initial atomic states) scales as N^2/ . This means that in order to keep the error probability bounded by Nε, with ε~ 1/ , one needs to use N/εphotons, or equivalently N separate "minimum-energy'' pulses: in this sense the pulses cannot, in general, be shared. The origin for this phenomenon is found in atom-field entanglement. These results may have important consequences for quantum logic and, in particular, for large-scale quantum computation.

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Julio Gea-Banacloche, Masanao Ozawa. 2006-11-13. Minimum-energy pulses for quantum logic cannot be shared. https://doi.org/10.1103/physreva.74.060301

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