Cross-correlation coefficient of field emission flicker noise from potassium submonolayers on tungsten

Abstract

Abstract In a field emission tube with two probe-holes the cross-correlation coefficient of current fluctuations from potassium submonolayers on tungsten has been measured. The cross-correlation coefficient depends on the probe-hole positions, i.e. on the substrate structure, and increases with emitter temperature and with potassium coverage; it is zero at the minimum of the noise power accompanying the work function minimum. These measurements seem to show for the first time the existence of spatial correlation in adsorbate submonolayers.