Multimode quantum memory with built-in spatiotemporal processing capabilities

In recent experiments performed in our group, we demonstrated a multimode quantum memory with built-in processing capabilities. We developed an ac-Stark based technique that allows reshaping of the stored spin waves in the spatial and temporal domain. With this, we are able to manipulate spin waves in a way reminiscent of single photons and demonstrate various protocols known from photonic systems. During the seminar, I will give an insight into the quantum memory experiment based on a cold atomic ensemble, where light is stored in the form of collective atomic excitations - spin waves. I will describe the basic principles of the light-atom interface and introduce the spin-wave manipulation technique based on spatially varying light shifts. Finally, I will discuss our most recent experiments including Hong-Ou-Mandel interference of heralded single spin waves as well as spin-wave based temporal far-field imaging achieving 20kHz spectral resolution and allowing bandwidth conversion for the atomic-based optical systems.