Electric-field-induced energy tuning of on-demand entangled-photon   emission from self-assembled quantum dots
  The scalability of quantum dot based non-classical light sources relies on the control over their dissimilar emission energies. Electric fields offer a promising route to tune the quantum dot emission energy through the quantum-confined Stark effect. However, electric fields have been mostly used for tuning the energy of single-photon emission from quantum dots, while electrical control over the energy of entangled-photon emission, which is crucial for building a solid-state quantum repeater using indistinguishable entangled photons, has not been realized yet. Here, we present a method to achieve electrical control over the energy of entangled-photon emission from quantum dots. The device consists of an electrically-tunable quantum diode integrated onto a piezoactuator. We find that, through application of a vertical electric field, the critical uniaxial stress used to eliminate the fine-structure-splitting of quantum dots can be linearly tuned. This allows realization of a triggered source of energy-tunable entangled-photon emission, an important step towards a solid-state quantum repeater application. 
Jiaxiang Zhang, Eugenio Zallo, Bianca H\"ofer, Yan Chen, Robert Keil,   Michael Zopf, Stefan B\"ottner, Fei Ding, and Oliver...
physics.optics cond-mat.mes-hall quant-ph