Probing Decoherence in Plasmonic Waveguides in the Quantum Regime

Abstract

$Q\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}m$ $p\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}s$ is an emerging field with a wide range of applications in quantum information science. Despite significant progress so far, it is not known how decoherence affects quantum plasmonic systems. This experimental study shows that damping of either amplitude or phase can lead to decoherence in these systems, and provides important information for designing plasmonic waveguide systems for loss-tolerant and phase-sensitive applications, such as quantum sensing and imaging. The techniques developed here may be useful for studying decoherence in other plasmonic structures, too, including nanoantennas, unit cells in metamaterials, and nanotraps for cold atoms.