Experimental observation of thermal fluctuations in single superconducting Pb nanoparticles through tunneling measurements

An important question in the physics of superconducting nanostructures is the role of thermal fluctuations (TFs) on superconductivity in the zero-dimensional limit. Here, we probe the evolution of superconductivity as a function of temperature and particle size in single, isolated Pb nanoparticles. Accurate determination of the size and shape of each nanoparticle makes our system a good model to quantitatively compare the experimental findings with theoretical predictions. In particular we study the role of TFs on the tunneling density of states (DOS) and the superconducting energy gap (Delta) in these nanoparticles. For the smallest particles h