We cosider the influence of diffraction on the storage of the quantum state of a pulse of squeezed light on a warm atomic ensemble with the collinear configuration of light fields. Even in the case of forward read out when both signal and driving light fields propagate in the same direction as during writing, the motion of atoms leads to the uncompensated phase shift. Because of this phase shift, the squeezed quadrature mixed with the stretched quadrature. As a result, the squeezing of the pulse can be significantly reduced. The article considers the influence of diffraction for different configurations of multimode resonant quantum memory and shows how to reduce this effect to its possible minimum.

In the case of a large number of quantum calculations, a situation may arise when the intermediate results of the calculations need to be stored for a given time. This work shows how to create a hybrid atom-light cluster state and realize a CZ gate in such a way that the results of its implementation are stored on long-lived degrees of freedom of the atomic ensemble and can be preserved for a long time.