The tunneling probe used in Scanning Tunneling Microscopy (STM) has been recently proposed as displacement sensor for resonant gravitational‐wave antennas. At present the performance of the tunnel probe as displacement sensor are limited by the 1/f noise in the tunnel current which, at room temperature, lowers of three orders of magnitude the expected sensitivity in the KHz range: preliminary results indicate that at liquid helium temperature the tunnel probe is a shot noise limited device. To understand the origin of the 1/f noise we are carrying on systematic measurements of the tunnel current noise as a function of the temperature and for different materials; the experimental results will be presented during the conference. Due to the quantum mechanical nature of the tunnel probe we believe that noise measurements as a function of the temperature can give also some useful information on the fundamental origin of the 1/f noise.
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