Magnetotransport in transparent single-wall carbon nanotube networks

Abstract

An experimental study of the low temperature magnetotransport in optically transparent single-wall carbon nanotube (SWNT) networks is reported. The SWNT network shows Coulomb gap variable-range hopping conduction at low temperatures. The magnetoresistance (MR) involves the interplay of two phenomena: a forward interference process leading to negative MR together with shrinkage of electronic wave function contributing to the positive MR. These two mechanisms fit the low-field data. The analysis of magnetotransport data gives an estimate for intrinsic parameters including localization length and Coulomb gap. The temperature dependence of the forward interference mechanism is shown to follow an inverse power-law dependence with an exponent close to 1, indicating the weak scattering process involved in the transport.