We report a high-performance cavity-enhanced electromagnetically-induced-transparency memory with warm atomic cell in which a scheme of optimizing the spatial and temporal modes based on the time-reversal approach is applied. The memory efficiency up to 67 ± 1% is directly measured and a noise level close to quantum noise limit is simultaneously reached. It has been experimentally demonstrated that the average fidelities for a set of input coherent states with different phases and amplitudes within a Gaussian distribution have exceeded the classical benchmark fidelities.

We proposeand experimentally demonstrate a compact quantum interferometerinvolving two optical parametric amplifiers and the squeezed statesgenerated within the interferometer are directly used for thephase-sensing quantum state. By both squeezing shot noise andamplifying phase-sensing intensity the sensitivity beyond thestandard quantum limit is deterministically realized and a minimumdetectable phase smaller than that of all present interferometersunder the same phase-sensing intensity is achieved. Thisinterferometric system has significantly potential applications in avariety of measurements for tiny variances of physical quantities.