Super-resolution spectroscopy using a quantum memory

While super-resolution techniques are widespread, they are rarely applied in fluorescence spectroscopy. One of the new methods for achieving super-resolution has been discovered through considering the quantum Cramer-Rao bound, which subsequently led to optimal projective measurement that facilitated resolution beyond the Rayleigh limit. Those measurements are especially difficult to implement in the spectro-temporal domain. We have devised a protocol that utilizes the spectro-temporal processing capabilities of our quantum memory. The atomic ensemble trapped and cooled in our laboratory has served as a processor for time-frequency quantum information, which allowed for optimal extraction of information from incident photons and beating the Rayleigh limit in spectroscopy.