Transport in gold cluster structures defined by electron-beam lithography

The near-room temperature current-voltage (I-V) characteristics of small structures made from the metal-cluster material Au-55[P(C6H5)(3)](12)Cl-6 were studied. It is shown that these electron-beam defined structures have highly nonlinear characteristics with features, including a threshold voltage and scaling behavior, which are consistent with Coulomb charging of individual Au-55 cores in a disordered array. Applied radio frequency signals introduce plateaus in the I-V characteristics, which demonstrates the presence of coherent tunneling in these cluster systems. (C) 1997 American Institute of Physics.