Resistance measurements and weak localisation in long SWNTs

In many I–V measurements, evidence has emerged pointing towards the existence of Luttinger-liquid behaviour in metallic single-walled carbon nanotubes (SWNTs), as expected for strongly interacting electrons in 1-d; such behaviour was observed via the power-law temperature and bias voltage dependence of the current through tunnelling contacts attached to the nanotubes. In particular, recent advances in the growth of extremely long nanotubes (>1 mm) have allowed for experimental measurements on the scaling behaviour of resistance in the individual, millimetre long SWNTs for the temperature range of 1.6–300 K. From the linear scaling of resistance, the temperature-dependent electron mean free path has been calculated for each temperature and, beyond the linear scaling regime, it has been observed that the resistance increases exponentially with length, indicating localisation behaviour. In this work, we analyse the results of the resistance measurements of different lengths of SWNT indicating the weak locali...