Light storage and retrieval in spherical semiconductor quantum dots with on-center hydrogen impurity in magnetic field

Abstract

We investigate the light propagation through the medium consisted of spherical semiconductor quantum dots with an on-center hydrogen impurity under the regime of the electromagnetically induced transparency. The weak probe and strong control laser couple to the medium, forming the three-level ladder-type coupling scheme. Maxwell-Bloch equations are solved numerically and analytically to obtain the spatial and temporal dependence of the probe pulse envelope. We observed that the probe pulse can be stored to and retrieved from the medium, with storage times of the order of nanoseconds being obtained. The external static magnetic field is shown to affect the energy level structure of the hydrogen impurity, reshaping the output probe pulse. We demonstrated that exposing the medium to cryogenic temperatures significantly increases the storage efficiency and storage time. These phenomena can greatly contribute to quantum information processing , leading to the construction of optical buffers, optical switches and quantum memories. • Slow light with the group velocity reduced by a factor 15 is achieved. • Storage times of the order of nanoseconds at room temperatures are obtained. • Approximate analytic results accurately describe the storage efficiency. • External magnetic field reshapes the output pulse and acts as an optical switch. • At cryogenic temperatures, storage times are increased to hundreds of nanoseconds.