English

Non-existence of invariant EPR correlation for two qudits, d>2

Quantum Physics 2011-09-08 v1

Abstract

The two qubit (spin 1/2) singlet state has invariant perfect EPR correlations: if two observers measure {\em any} identical observables the results are always perfectly (anti-)correlated. We show that no such correlations exists in ddd\otimes d pure or mixed bipartite quantum states if d3d\geq3. This points that two qubit singlets are high-quality quantum information carriers in long distance transmission: their correlations are unaffected by identical random unitary transformations of both qubits. Pairs of entangled quddits, d>2d>2, do not have this property. Thus, quddit properties should be rather exploited only in protocols in which transmission is not a long distance one.

Keywords

Cite

@article{arxiv.1109.1447,
  title  = {Non-existence of invariant EPR correlation for two qudits, d>2},
  author = {Shengshi Pang and Shengjun Wu and Marek Zukowski},
  journal= {arXiv preprint arXiv:1109.1447},
  year   = {2011}
}

Comments

4 pages, 2 figures