Quantum sensors based on weak-value amplification cannot overcome decoherence

摘要

Sensors that harness exclusively quantum phenomena (such as entanglement) can achieve superior performancencompared to those employing only classical principles. Recently, a technique based on postselected, weaklynperformed measurements has emerged as a method of overcoming technical noise in the detection and estimationnof small interaction parameters, particularly in optical systems. The question of which other types of noise may bencombated remains open.We here analyze whether the effect can overcome decoherence in a typical field-sensingnscenario. Benchmarking a weak, postselected measurement strategy against a strong, direct strategy, we concludenthat no advantage is achievable, and that even a small amount of decoherence proves catastrophic to the weak-valuenamplification technique.