Experimental optimal orienteering via parallel and antiparallel spins

Abstract

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.

References in corpus (5)

• Entanglement detection
• Reference frames, superselection rules, and quantum information
• Universally Fisher-Symmetric Informationally Complete Measurements
• Implementation of generalized measurements on a qudit via quantum walks
• The Elegant Joint Quantum Measurement and some conjectures about N-locality in the Triangle and other Configurations