Self-Heating Hotspots in Superconducting Nanowires Cooled by Phonon Black-Body Radiation

Controlling thermal transport is important for a range of devices and technologies, from phase change memories to next-generation electronics. This is especially true in nano-scale devices where thermal transport is altered by the influence of surfaces and changes in dimensionality. In superconducting nanowire single-photon detectors, the thermal boundary conductance (TBC) between the nanowire and the substrate it is fabricated on influences most of the performance metrics that make these detectors attractive for applications. This includes the maximum count rate, latency, jitter, and quantum efficiency. Despite its importance, the study of TBC in superconducting nanowire devices has not been done systematically, primarily due to the lack of a straightforward characterization method. Here, we show that simple electrical measurements can be used to estimate the TBC between nanowires and substrates and that these measurements match acoustic mismatch theory across a variety of substrates. Numerical simulations allow us to refine our understanding, however, open questions remain. This work should enable thermal engineering in superconducting nanowire electronics and cryogenic detectors for improved device performance.

Development of Cryogenic Detectors for Neutrinoless Double Beta Decay Searches with CUORE and CUPID

Searching for neutrinoless double beta decay is a top priority in particle and astroparticle physics, being the most sensitive test of lepton number violation and the only suitable process to probe the Majorana nature of neutrinos. In order to increase the experimental sensitivity for this particular search, ton-scale detectors operated at nearly zero-background conditions with a low keV energy resolution at the expected signal peak are required. In this scenario, cryogenic detectors have been proven effective in addressing many of these issues simultaneously. After long technical developments, the Cryogenic Underground Observatory for Rare Events (CUORE) experiment established the possibility to operate large-scale detectors based on this technology. Parallel studies pointed out that scintillating cryogenic detectors represent a suitable upgrade for the CUORE design, directed towards higher sensitivities. In this work, we review the recent development of cryogenic detectors, starting from the state-of-the-art and outlying the path toward next-generation experiments.

Development of Cryogenic Detectors for Neutrinoless Double Beta Decay Searches

Searching for neutrinoless double beta decay is a top priority in particle and astroparticle physics, being the most sensitive test of lepton number violation and the only suitable process to probe the Majorana nature of neutrinos. In order to increase the experimental sensitivity for this particular search, ton-scale detectors operated at nearly zero-background conditions with a few keV energy resolution are required. In this scenario, cryogenic detectors have proven effective in addressing many of these issues simultaneously. After long technical developments, the CUORE experiment established the possibility to operate large scale detectors based on this technology. Parallel studies pointed out that scintillating cryogenic detectors represent a suitable upgrade for the CUORE design, directed towards higher sensitivities. In this work, we review the recent development of cryogenic detectors, starting from the status of the art and outlying the path toward next-generation experiments.

Cryogenic Dark Matter Searches

In the decades-old quest to uncover the nature of the enigmatic dark matter, cryogenic detectors have reached unprecedented sensitivities. Searching for tiny signals from dark matter particles scattering in materials cooled down to low temperatures, these experiments look out into space from deep underground. Their ambitious goal is to discover non-gravitational interactions of dark matter and to scan the allowed parameter space until interactions from solar and cosmic neutrinos are poised to take over.

Cryogenic detectors exploring new phenomena in physics and astrophysics

The potential to measure small energy transfers with very high energy resolutions motivated the development of cryogenic detectors to search for dark matter in the universe, the neutrino mass, neutrinoless double beta decay, and new phenomena in astrophysics. Other fields like material and life sciences also benefited from these developments.