Characterizing the dark count rate of a large-format MKID array.

We present an empirical measurement of the dark count rate seen in a large-format MKID array identical to those currently in use at observatories such as Subaru on Maunakea. This work provides compelling evidence for their utility in future experiments that require low-count rate, quiet environments such as dark matter direct detection. Across the bandpass from 0.

Membraneless Phonon Trapping and Resolution Enhancement in Optical Microwave Kinetic Inductance Detectors.

Microwave kinetic inductance detectors (MKIDs) sensitive to light in the ultraviolet to near-infrared wavelengths are superconducting microresonators that are capable of measuring photon arrival times to microsecond precision and estimating each photon's energy. The resolving power of nonmembrane MKIDs has remained stubbornly around 10 at 1  μm despite significant improvements in the system noise. Here we show that the resolving power can be roughly doubled with a simple bilayer design without needing to place the device on a membrane, avoiding a significant increase in fabrication complexity.