Quantum Fisher information, which serves as a powerful tool for quantifying the sensitivity of quantum states to parameter variations, has profound implications for quantum metrology. In this work, we establish a general framework for characterizing both the wave and particle features in multipath interferometers using the quantum Fisher information. Furthermore, we derive a complete complementarity relation involving the interference (wave feature), the predictability (particle feature), and the quantum $f$ entropies. As an illustration, we calculate the relevant quantities for the two-path interferometers. Compared with two related characterizations about the complementarity relations, we emphasize that the quantum Fisher information serves as the unified figure of merit for both wave and particle properties. This work builds the connections between the quantum Fisher information and the foundational complementarity principles, offering a fresh and unified perspective for the wave-particle duality in multipath interferometers.

Close

PrevNext

View figure in article

• Quantum foundations
• Quantum information theory
• Quantum parameter estimation