Compare Papers

Paper 1

Locally inequivalent four qubit hypergraph states

Xiao-yu Chen, Lei Wang

Year
2014
Journal
arXiv preprint
DOI
arXiv:1409.0928
arXiv
1409.0928

Hypergraph states as real equally weighted pure states are important resources for quantum codes of non-local stabilizer. Using local Pauli equivalence and permutational symmetry, we reduce the 32768 four qubit real equally weighted pure states to 28 locally inequivalent hypergraph states and several graph states. The calculation of geometric entanglement supplemented with entanglement entropy confirms that further reduction is impossible for true hypergraph states.

Open paper

Paper 2

Security bound of cheat sensitive quantum bit commitment

Guang Ping He

Year
2014
Journal
arXiv preprint
DOI
arXiv:1407.7517
arXiv
1407.7517

Cheat sensitive quantum bit commitment (CSQBC) loosens the security requirement of quantum bit commitment (QBC), so that the existing impossibility proofs of unconditionally secure QBC can be evaded. But here we analyze the common features in all existing CSQBC protocols, and show that in any CSQBC having these features, the receiver can always learn a non-trivial amount of information on the sender's committed bit before it is unveiled, while his cheating can pass the security check with a probability not less than 50%. The sender's cheating is also studied. The optimal CSQBC protocols that can minimize the sum of the cheating probabilities of both parties are found to be trivial, as they are practically useless. We also discuss the possibility of building a fair protocol in which both parties can cheat with equal probabilities.

Open paper