Two-photon absorption of path-entangled number states

In this contribution, we present our studies of two-photon absorption of path-entangled number states $\vert $M,M+2$>+\vert $M+2,M$>$. We show theoretically that these states with detection scheme based on a two-photon absorber are super-resolving and provide high absorption rate with a visibility of 20{\%} in the limit of large M. We also discuss sensitivity of a two-photon absorber based detection scheme of above mentioned states and show that the phase sensitivity suffers significant reduction.