UCAMThe University of Cambridge has facilities for fabrication of GaAs electron pumps (molecular beam epitaxy, GaAs processing cleanroom, electron beam lithography) and low-temperature measurements of these devices. UCAM has collaborated with NPL in the development of single-electron current sources since 2007, most recently with SIB07-REG2 of EMRP JRP SIB07 Qu-Ampere. UCAM also has expertise in fabricating multiplexed arrays of mesoscopic GaAs devices. In this project, UCAM will perform device fabrication and characterisation of GaAs pump arrays.