Energy-tunable sources of entangled photons: A viable concept for solid-state-based quantum relays

We propose a new method of generating entangled photon pairs with wavelength on demand. The method uses a six-legged semiconductor-piezoelectric device capable of dynamically reshaping the electronic properties of self-assembled quantum dots via anisotropic strain-engineering. Theoretical models based on kp theory in combination with finite element calculations are used to demonstrate that the energy of the polarization-entangled photons emitted by quantum dots can be tuned in a range larger than 100 meV without affecting the degree of entanglement of the quantum source. These results pave the way towards the deterministic implementation of QD entanglement resources in all electrically-controlled solid-state quantum relays.