Coulomb blockade related to mutual Coulomb interaction in an external environment in an array of single tunnel junctions connected to Ni nanowires

The Coulomb blockade (CB), which depends on the mutual Coulomb interaction (MCI) in external electromagnetic environments (EME's), is reported in an a rray system of single tunnel junctions connected directly to disordered Ni nanowires (i.e., an array of a disordered Ni nanowire/Al2O3/Al system locat ed in parallel), fabricated using a nanoporous Al film template. The observ ed zero-bias conductance (G(0)) anomaly and its linear G(0) versus temperat ure relation qualitatively agree with the CB observations of Zeller and Gia ever and of Cleland, Schmidt, and Clarke. The CB is also quantitatively con firmed from the extended Zeller-Giaever model in a tunnel-junction array. I n the high-voltage region, only one-dimensional (1D) MCI following the Alts huler-Aronov formula in a disordered Ni wire dominates the conductance mech anism with the absence of the CB. In contrast, in the lower-voltage region, the CB mentioned above emerges at temperatures below a phase-transition te mperature (T-c), accompanied by the 1D MCI in the Ni wire. The MCI plays th e key roles of high-impedance EME and transmission line following the phase correlation theory of the CB. It is found that the CB is very sensitive to the diffusion coefficient (D) of the MCI, resulting in the linear T-c-vs-D -1/2 relation. For this relation, we propose as one possible model, that th e charging energy of the CB competes with the energy quantum of fluctuation of the Nyquist phase breaking caused by multiple Coulomb scattering in the Ni nanowire. This linear T-c-vs-D-1/2 relation is reconfirmed by the Ni-wi re diameter dependence of T-c. The magnetic field dependence of the G(0)-ve rsus-temperature relation obviously supports the actual presence of T-c wit h different conductance mechanisms for the temperatures above and below T-c .