Applications of low-temperature microwave techniques to the measurement of gravity waves and quantum measurement of macroscopic systems

Recent research into cryogenic (4 K) and ultra-cryogenic (down to 15 mK) parametric transducers for resonant-mass detectors is presented. Current technology is capable of operating with a noise energy equivalent to one mK in noise temperature. This includes the 4 K cryogenic detector, Niobe, at the University of Western Australia (UWA). It is shown that a large improvement can be achieved through the use of low loss acoustic materials, new low noise microwave technology and ultra-cryogenic techniques. It is shown that this technology could measure the standard quantum limit of a macroscopic resonant-mass displacement detector. (C) 2000 Elsevier Science B.V. All rights reserved.