Donor-bound excitons in Cl doped ZnSe quantum wells

Quantum information processing heavily depends on the ability to generate the high number of indistinguishable single photons and to interface them with long-lived coherent spin states. Quantum dots as emerged as promising scalable solid-state platforms by offering bright photon emissions. However, epitaxially grown quantum dots are not immune to size variations and they suffer short coherence times due to interactions with host material nuclear spin bath.

Quantum emission from electron-bound to F donor impurities in bulk ZnSe and ZnSe quantum wells are shown previously. Unlike quantum dots, these emitters show small inhomogeneous broadening¹, short decay times^1, and long-coherence times². Together with the possibility of spin purification of the host material, donor impurities in such quantum wells may open the possibility to generate efficient spin-photon interfaces.

Here we investigate emission properties of donor bound excitons in Cl doped ZnSe/ZnMgSe quantum wells. Spectral properties of emitters are investigated in cryogenic temperatures. Time-resolved fluorescence experiments show that these emitters exhibit sub-nanosecond decay times. Second-order time-correlation measurements prove the single-photon emission.