Quantum Repeaters and Bell Analyzers Photonic Crystal (PC) cavities with embedded Quantum Dots (QD's) can be used to realize a full Bell State Analyzer and a Quantum Repeater. The quantum dots have a state which is coupled to the cavity, and a dark state that is uncoupled. When the dot is in a coupled state, a phase shift is imparted to photons scattered off of the cavity. Collision of photons from two cavities containing the quantum dots can be used to prepare the dots in an entangled state. The schematic of such an experiment in shown on the right.

We have recently proposed a Bell state analyzer and a Quantum repeater based on Quantum Dot PC cavity interaction in the Weak, but high Purcell Factor Regime. The relevant work can be found in the following two references:

Dipole induced transparency in drop-filter cavity-waveguide systems

Dispersive properties and giant Kerr non-linearities in Dipole Induced Transparency

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