Experimental Optimal Orienteering via Parallel and Antiparallel Spins

Autor: Huangjun Zhu, Guang-Can Guo, Guo-Yong Xiang, Chuan-Feng Li, Zhibo Hou, Jiangwei Shang, Jun-Feng Tang
Rok vydání: 2020
Předmět:
Zdroj: Physical Review Letters. 124
ISSN: 1079-7114
0031-9007
DOI: 10.1103/physrevlett.124.060502
Popis: Antiparallel spins are superior in orienteering to parallel spins. This intriguing phenomenon is tied to entanglement associated with quantum measurements rather than quantum states. Using photonic systems, we experimentally realize the optimal orienteering protocols based on parallel spins and antiparallel spins, respectively. The optimal entangling measurements for decoding the direction information from parallel spins and antiparallel spins are realized using photonic quantum walks, which is a useful idea that is of wide interest in quantum information processing and foundational studies. Our experiments clearly demonstrate the advantage of antiparallel spins over parallel spins in orienteering. In addition, entangling measurements can extract more information than local measurements even if no entanglement is present in the quantum states.
Databáze: OpenAIRE