2024/07/21 by Governale, Michele, Schönenberger, Christian, Scarlino, Pasquale +1 · 2 citations
#FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2407.15109
As a waveguide circuit QED architecture, we investigate theoretically the single-photon pair emission of a Cooper pair splitter composed of two double quantum dots, each coupled to a microwave transmission line. We find that this system can generate frequency-entangled photon pairs in the left and right transmission lines, specifically a superposition of two photon wave packets at different frequencies. The frequency entanglement of the two photons arises from the particle-hole coherent superposition (i.e., Andreev bound states) involving the delocalized entangled spin singlet. We also estimate a lower bound for the efficiency of entangled photon-pair generation, accounting for the presence of nonradiative processes such as phonon emissions. Our proposal is realistic and achievable with state-of-the-art techniques in quantum microwave engineering with electostatically defined semiconducting quantum dots.