Quantum-dot spins and cavity QED

Quantum dots are semiconductor structures that confine electron and hole motion in all three dimensions. A single electron spin trapped in a quantum dot is also a promising semiconductor-based system to study various quantum optical phenomena. As a key step towards manipulation of a confined spin, we have recently demonstrated all-optical state preparation of a quantum-dot electron spin with a fidelity exceeding 99.8% via optical pumping. I will present a detailed analysis of optical pumping, hyperfine-induced spin-filp, and co-tunneling rates in this system under different conditions. I will further discuss challenges and solutions to incorporating spins into photonic crystal nanocavities.