Detection of the ideal resource for multiqubit teleportation**Project supported by the National Natural Science Foundation of China (Grant Nos. 11401032, 11275131, and 61473325), the Foundation of Beijing Information Science and Technology University, China (Grant No. 1425032), and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of China.

Abstract

We give a sufficient condition for detecting the entanglement resource for perfect multiqubit teleportation. The criterion involves only local measurements on some complementary observables and can be experimentally implemented. It is also a necessary condition for full separability of multiqubit states. Moreover, by proving the optimality of teleportation witnesses, we solve the open problem in Phys. Rev. A 86, 032315 (2012).