Is Entanglement Sufficient to Enable Quantum Speedup?
Abstract
According to the Gottesman-Knill theorem, any quantum algorithm utilising operations chosen exclusively from a particular restricted set are efficiently simulable by a classical computer. Since some of these algorithms involve entangled states, it is commonly concluded that entanglement is insufficient to enable quantum speedup. As I explain, however, the operations belonging to this set are precisely those which will never yield a violation of the Bell inequalities. Thus it should be no surprise that entangled quantum states which only undergo operations in this set are efficiently simulable classically. What the Gottesman-Knill theorem shows us is that it is possible to use an entangled state to less than its full potential. Nevertheless, there is a meaningful sense in which entanglement is sufficient for quantum speedup: an entangled quantum state provides sufficient physical resources to enable quantum speedup, whether or not one elects to use these resources fully.
Cite
@article{arxiv.1207.5236,
title = {Is Entanglement Sufficient to Enable Quantum Speedup?},
author = {Michael E. Cuffaro},
journal= {arXiv preprint arXiv:1207.5236},
year = {2013}
}
Comments
Only minor changes from last version. Comments and criticisms are welcome. This article has been superseded by arXiv:1310.0938