Asymptotic role of entanglement in quantum metrology
Asymptotic role of entanglement in quantum metrology
Quantum systems allow one to sense physical parameters beyond the reach of classical statistics---with resolutions greater than $1/N$, where $N$ is the number of constituent particles independently probing a parameter. In the canonical phase-sensing scenario the Heisenberg limit $1/{N}^{2}$ may be reached, which requires, as we show, both the relative …