Influence of phase fluctuation in external environment on Coulomb blockade in an array system of single tunnel junctions/Ni nanowires

Correlation of Coulomb blockade (CB) with phase fluctuation caused by mutual Coulomb interaction is reported in an array system of single tunnel junctions directly connected to disordered Ni nanowires. At the voltages lower than CB voltage, temperature dependence of the normalized resistance is classified to the following two regimes by a phase transition temperature $(Tc),$ (1) mutual Coulomb interaction regime $(T>Tc)$ and (2) CB regime $(T<Tc).$ It is found that this $Tc$ is very sensitive to a diffusion coefficient (D) of the mutual Coulomb interaction, resulting in a linear $Tc$ vs $D1/2$ relation. This relation is interpreted as a result of the competition between the charging energy of the CB and the phase fluctuation energy caused by the multiple Coulomb scattering in the Ni nanowire. It is also reconfirmed by the wire diameter dependence of $Tc.$