1/f noise and mechanisms of the conductivity in carbon nanotube bundles

Experimental results are reported of the investigation of conductivity mechanisms in metallic single-wall carbon nanotube (SWCNT) bundles in a wide temperature range from 4.2 K to 300 K. The temperature dependence of the resistance and noise parameters - the logarithmic slope of the current dependence of noise as well as the normalized current noise - are compared. Remarkable changes in noise characteristics are registered at temperatures typical of the transition from hopping conductivity to Luttinger liquid conductivity and the transition from Luttinger liquid conductivity to diffusion conductivity. In the first transition region, the slope of the normalized noise level of the current changes significantly as a function of temperature. In the region of diffusion conductivity, a stronger variation of the normalized noise level is revealed. These changes in noise properties are correlated with changes in the transport characteristics of SWCNT bundles that allow us to adequately explain the mechanisms of conductivity in the system.