Quantum Cascade of Photons in Semiconductor Quantum Dots

Abstract
We have obtained pairs of correlated single photons from the emission cascade of an isolated InAs quantum dot. The cross-correlation function of the two photons in a pair exhibits the coexistence of asymmetric bunching and antibunching features, which is the signature for their sequential emission with a definite order. This observation opens the way to the use of semiconductor quantum dots as triggered sources of photon pairs with strong quantum correlations for quantum information applications.