Development of a Spatially Resolved ³He Quasi-Particle Detector

Andreev surface bound sates are known to exist on the boundaries of superfluid (Formula presented.) He-B. However, the detailed nature of their interaction with bulk quasi-particles is not well known. In a manner similar to angle-resolved photo-emission spectroscopy, surface states can be probed by measuring the change in momentum of bulk quasi-particles scattered from the surface. In order to make such a measurement, we have designed a spatially resolved quasi-particle detector. The detector consists of an array of micro-machined resonators, which are sensitive to quasi-particle flux. The detector is based on previously developed micro-machined resonators, which have been successfully used to study superfluid (Formula presented.) He-B and (Formula presented.) He. Presented here is the design of the detector and the fabrication procedure.