Memory for light and quantum communication

Optical communication protocols that employ quantum nature of light are very secure. Their practical development is however hindered by losses, which reduce the communication range by a few tens of kilometers. This problem can be remedied by means of quantum repeaters, which effectively enhance the data transfer rate without compromising security. Implementation of quantum repeaters requires quantum memory for light - a tool that permits high-fidelity storage and retrieval of quantum optical states. We will discuss ways in which such memory can be implemented, as well as the current state of the art, progress, and challenges faced by the field.