Two-photon nonlinearity by an excitonic system placed in a cavity
Kazuki Koshino, Hajime Ishihara · Physical Review A · 2005
We have investigated the two-photon nonlinearity attained by a finite-sized excitonic system placed inside of a cavity, paying attention to the dependence on the system size $N$. The two-photon nonlinearity is evaluated by utilizing semiclassical optical responses. In the quantum-dot limit, the excitonic system behaves as a single two-level system with an enhanced coupling to the cavity mode. In the bulk limit, the nonlinear phase shift decreases as $N$ is increased, proportionally to ${N}^{\ensuremath{-}1∕2}$.