Nonlinear gain-absorption property of a weak probe field in a solid-state quantum well

For a three-level semiconductor quantum well system with a closed-loop configuration, we find that, owing to the quantum interference and coherence, the large enhancement of probe gain can be achieved under appropriate conditions. In particular, the relative phase of the applied fields plays an important role in realizing the large gain of the probe field. Our study is much more practical than its atomic counterpart due to its flexible design and the wide adjustable parameters. Thus, it may provide some possibilities for obtaining potential applications in solid-state quantum computation and quantum communication.