2018/01/31 by Daniel Huber, Marcus Reindl, Saimon Filipe Covre da Silva +8 · 2 citations
Computer Science · Engineering · Physics and Astronomy · #Biexciton #Degenerate energy levels #Dephasing #Exciton #Fine structure #Photon #Photon entanglement #Physics #Quantum #Quantum Information and Cryptography #Quantum decoherence #Quantum dot #Quantum entanglement #Quantum information science #Quantum mechanics #Quantum network #Quantum sensor #Semiconductor Lasers and Optical Devices #Semiconductor Quantum Structures and Devices #Spontaneous parametric down-conversion #quant-ph
paper · pdf · doi:10.1103/physrevlett.121.033902
published as Phys. Rev. Lett. 121, 033902 (2018)
openalex publication_date 2018/07/18 · arxiv created 2018/10/10 · arxiv updated 2018/10/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report on the observation of nearly maximally entangled photon pairs from semiconductor quantum dots, without resorting to postselection techniques. We use GaAs quantum dots integrated on a patterned piezoelectric actuator capable of suppressing the exciton fine structure splitting. By using a resonant two-photon excitation, we coherently drive the biexciton state and demonstrate experimentally that our device generates polarization-entangled photons with a fidelity of 0.978(5) and a concurrence of 0.97(1) taking into account the nonidealities stemming from the experimental setup. By combining fine-structure-dependent fidelity measurements and a theoretical model, we identify an exciton spin-scattering process as a possible residual decoherence mechanism. We suggest that this imperfection may be overcome using a modest Purcell enhancement so as to achieve fidelities >0.99, thus making quantum dots evenly matched with the best probabilistic entangled photon sources.