Meissner-effect single-particle detector (1/2): proof-of-concept and thermal analysis

We present work on harnessing the superconducting Meissner effect to create magnetic Transition Edge Sensors (TES) for the detection of single particles. Our devices consist of a superconducting absorber surrounded by an inductive pickup loop. If the absorber is biased within its superconducting transition, additional energy from an incoming particle or photon changes the magnetic permeability of the absorber, which is read out by the pickup loop. In this configuration, the absorber is physically decoupled from the measurement electronics, which may be beneficial for thermal control and noise. A DC magnetic field bias enables in-situ tuning of the transition temperature as well as the possibility of tuning dynamic range.

For our prototype devices the change in the magnetic flux from a microscale disk of electrodeposited tin may be detected by a planar pickup loop consisting of a niobium thin film. We experimentally demonstrated the magnetic superconducting transition of a microscale tin disk using four-terminal alternating-current measurement of the niobium pickup coil. We observe a shift in the magnetic superconducting transition temperature for a device subjected to a cryogenic source of ionizing radiation. This allowed us to characterize thermal properties of the prototype device. From the experimental data, we determined a design framework for operating Meissner TES detectors in terms of sensitivity and response time, directed toward single particle cryogenic microcalorimetry.