  The composition of dark matter is one of the puzzling topics in astrophysics.
To address this issue, several experiments searching for the existence of
axions have been designed, built and realized in the last twenty years. Among
all the others, light shining through walls experiments promise to push the
exclusion limits to lower energies. For this reason, effort is put for the
development of single-photon detectors operating at frequencies $<100$ GHz.
Here, we review recent advancements in superconducting single-photon detection.
In particular, we present two sensors based on one-dimensional Josephson
junctions with the capability to be in situ tuned by simple current bias: the
nanoscale transition edge sensor (nano-TES) and the Josephson escape sensor
(JES). These two sensors are the ideal candidates for the realization of
microwave light shining through walls (LSW) experiments, since they show
unprecedented frequency resolutions of about 100 GHz and 2 GHz for the nano-TES
and JES, respectively.
