Quantum phase estimation using a class of entangled states: NOON-type states

Su-Yong Lee, Chang-Woo Lee, Jaehak Lee, Hyunchul Nha

Published 2015-05-22Version 1

We address how a quantum phase estimation using a $|\phi 0\rangle+|0\phi\rangle$-type entangled state can be controllable by Mandel Q-factor of a single-mode state $|\phi\rangle$. From a simple form of the quantum Fisher information, we show that quantum Cram\'er-Rao bound can be enhanced with super-Poissonianity of the single-mode component. For an optical phase estimation, these bounds can also be achieved in a certain range of unknown phases by performing a parity measurement at the output. On the other hand, over an entire range $[0,2\pi]$ of unknown phase shifts, we show that the phase-shift range for beating shot-noise limit can be enlarged with sub-Poissonianity of the single-mode component.