Particle Sensor Based on Nano-scale SQUIDs

摘要

Superconducting devices, based on their quantum nature and on the losv-noise advantages gained by cryogenic operation, are already well established for the highlysensitive detection of electromagnetic radiation. We extend the principle to include the detection of single energetic particles such as photons, atoms or macromolecules. Rather than detecting a resistive transition, which is a well-known technique, our novel detector responds to incoming energy through a transient change in the inductance. We have theoretically estimated the energy sensitivity of such a sensor, in the case where the heat absorber is incorporated within the sensitive area of a nano-scale SQUID (Superconducting Quantum Interference Device) which acts as an inductive readout device. Recent results on the experimental haracterization of prototype devices in the temperature range 1.5K- 8 K are presented, and ongoing work which is intended to achieve smaller device dimensions together with lower operating temperatures is described.