Efficient discrimination schemes for unextendible product bases with strong quantum nonlocality

Entanglement is a central resource in quantum information science; therefore, it is important to design local discrimination protocols that minimize resource consumption. In this paper, we propose three entanglement-allocation schemes for the local discrimination of particular unextendible product bases (UPB) exhibiting strong quantum nonlocality in a $3 \otimes 3 \otimes 3$ system. By exploiting the structural features of these UPB and the operational advantages of maximally entangled states, we further extend our protocols to strongly nonlocal UPB in $d \otimes d \otimes d$ systems. In particular, we show that these UPB can be perfectly distinguished with only two maximally entangled states. Moreover, a resource-cost analysis indicates that our protocols, which avoid quantum teleportation whenever possible, can reduce the entanglement consumption. These results not only facilitate resource-efficient quantum information processing, but also provide further insight into the operational role of maximally entangled states.