QUANTIZATION EFFECTS IN THE CONDUCTANCE OF METALLIC CONTACTS AT ROOM-TEMPERATURE

We present measurements on conductance quantization in atomic scale me tallic constrictions at room temperature. Conductance measurements as a function of constriction size reveal pronounced horizontal plateaus separated by sharp discrete steps. Most individual conductance plateau s are close to integer multiples of the fundamental conductance unit b ut definite deviations are also present. After averaging over many con tact configurations, conductance quantization is seen clearly and more prominently than in similar recent low temperature measurements on th e same metals.