Tunable Cherenkov radiation-based detectors via plasmon index enhancement

A recent study [PRB 100, 075427 (2019)], finally, demonstrated plasmon-analog of refractive index enhancement in metal nanostructures, which has already been studied in atomic clouds for several decades. Here, we simply utilize this phenomenon for achieving tunable enhanced Cherenkov radiation in metal nanostructures. Besides enabling Cherenkov radiation from slow-moving particles, or increasing its intensity, the phenomenon can be used also in tuning the velocity cutoff of particles contributing the Cherenkov radiation. This allows a tunable analysis of the contributing particles. The phenomenon can also be integrated into lattice metal nanostructures, for further enhancement, where a high density of photonic states is present and the threshold for the Cherenkov radiation can even be lifted.