Influence of electron-phonon scattering for an on-demand quantum dot single-photon source using cavity-assisted adiabatic passage

摘要

We study the role of electron-phonon scattering for a pulse-triggered quantum dot single-photon source whichutilizes a modified version of stimulated Raman adiabatic passage and cavity coupling. This on-demand source iscoherently pumped with an optical pulse in the presence of a continuous-wave laser drive, allowing for efficientgeneration of indistinguishable single photons with polarizations orthogonal to the applied fields. In contrastto previous studies, we explore the role of electron-phonon scattering on this semiconductor system by using apolaron master equation approach to model the biexciton-exciton cascade and cavity mode coupling. In additionto background zero-phonon-line decoherence processes, microscopic electron–acoustic-phonon coupling, whichusually degrades the indistinguishability and efficiency of semiconductor photon sources, is rigorously takeninto account. We study how different system parameters (including cavity and laser detunings, cavity spectralwidth, temperature) affect the device performance and contrast the relative influence of intrinsic phonon couplingwith other dephasing mechanisms.We describe how this biexciton-exciton cascade scheme allows for true singlephotons to be generated with over 90% quantum indistinguishability and efficiency simultaneously using realisticexperimental parameters. We also show how the double-field dressing can be probed through the cavity-emittedspectrum.