A multitasking device based on electromagnetically induced transparency in optical cavities

摘要

Quantum memories and optical transistors are elementary building blocks for the implementation of many devices for quantum computers and quantum communication. The realization of experiments that can perform both capabilities in the same setup can open an avenue of possibilities in the development of such practical quantum technologies. We theoretically investigate the feasibility of implementing a quantum memory and an optical transistor in the same setup using a combination of electromagnetically induced transparency and cavity quantum electrodynamics (cavity-EIT) for single-and two-sided cavity configurations. This was accomplished by considering a single three-level atom in Lambda configuration coupled to a single electromagnetic mode of the cavity and a suitable temporal shape for the EIT control field. An optical transistor in cavity-EIT can be realized in a symmetric cavity with two output channels while a high efficient quantum memory must be performed in a single-sided one. From the master equation and input-output formalisms for the intracavity and outside fields, respectively, we obtain the upper bound of 50% for the memory efficiency with perfect transistor action in two-sided cavities and values close to 100% for the efficiency with a limited transistor effect for the single-sided setup in the high cooperativity regime. Thus, we showed that a dual device, which operates as a quantum memory and an optical transistor in the same setup of cavity-EIT, can be accomplished with some limitation in one of those capabilities.