A spectrally-multiplexed Bell-state measurements

Abstract

In this master’s thesis we report on the characterization of spectral-multiplexed Bell-state measurement, a fundamental building block of spectral-multiplexed quantum repeater architecture. To test our hypothesis, we show an experimental setup that resembles an MDI-QKD setup, but multiplexed in frequency. The result is an increased secret key rate thanks to the individual contributions of each spectral mode. We also report characterization of all relevant degrees of freedom that affect Bell-state measurement efficiency, such as spectral-demultiplexing, Hong-Ou-Mandel interference and qubit generation. To finalize, we discuss on possible improvements and lay down the steps to follow to achieve spectrally-multiplexed quantum teleportation.