We present and experimentally show a novel protocol for distributing secret information between two and only two parties in a N-party single-qubit Quantum Secret Sharing (QSS) system. We demonstrate this new algorithm with N = 3 active parties over ~6km of telecom. fiber. Our experimental device is based on the Clavis<sup>2</sup> Quantum Key Distribution (QKD) system built by ID Quantique but is generalizable to any implementation. We show that any two out of the N parties can build secret keys based on partial information from each other and with collaboration from the remaining N − 2 parties. This algorithm allows for the creation of two-party secret keys were standard QSS does not and significantly reduces the number of resources needed to implement QKD on a highly connected network such as the electrical grid.
Zinc oxide is a wide bandgap insulator with significant promise for applications in optics, electro-optics and electronics.
However, there are challenges in growing high-quality material, and a prominent visible luminescence channel due to
defect recombination competes with the ultraviolet band-edge exciton decay. Here we demonstrate the possibility of
characterizing a specific defect by means of Purcell enhanced exciton-plasmon dynamics and photoluminescence.
Nanostructured metal-ZnO systems provide an ideal workbench for studying the dynamics of exciton-plasmon coupling.
In order to characterize the interactions, we grew tri-layer structures comprising thin films of ZnO, variable-thickness
spacer layers of MgO, and thin films of Ag or Au. Analysis of the photoluminescence of these structures as a function
of increasing MgO thickness confirms the existence of surface plasmon polariton-exciton coupling through Purcell
enhancement of the excitonic emission for MgO films thinner than 30 nm, and through emission at the SPP resonance
for MgO films thicker than 30 nm. Further, we demonstrate the enhancement of the ZnO impurity photoluminescence
through dipole-dipole scattering with Ag and Au LSPs. Preliminary degenerate band-edge pump-probe measurements
confirm the conclusions developed from photoluminescence measurements. In order to disentangle and further quantify
the interactions seen in these systems, we are lithographically patterning metal nanoparticle arrays and metal hole arrays
on ZnO quantum wells and beginning to perform white-light pump-probe spectroscopy to fully characterize the
dynamics of energy transfer within these systems.