Electromagnetically Induced Transparency in Semiconductors

This final technical report summarizes research supported by ARO in two areas electromagnetically induced transparency EIT from electron spin coherence and cavity QED with nitrogen vacancy NV centers in diamond nanocrystals. We have developed three different schemes to realize EIT using electron spin coherence in semiconductor quantum wells. The three schemes include the use of V-type three-level systems via heavy hole excitonic transitions in an external magnetic field in the Voigt geometry, the use of V-type three-level systems via light hole excitonic transitions in a waveguide geometry and in the absence of an external magnetic field, and the use of a lamda-type three-level system in a mixed-type quantum well structure. We have achieved the breakthrough of realizing the strong coupling regime in cavity QED by coupling NV centers in diamond nanocrystals to whispering gallery modes in a deformed fused silica microsphere. In addition, our improved understanding on how electron spin coherence contributes to nonlinear optical processes in semiconductors has also led to the demonstration of a spin manipulation scheme that controls both the amplitude and phase of electron spin precessions.