Self-heating of metallic carbon nanotube bundles in the regime of the Luttinger-liquid conductivity

Abstract

The conductivity of bundles of carbon single-walled nanotubes with metallic conductivity (metallic nanotubes) is investigated over the wide temperature range 4.2–330 K and electrical fields up to 50 V. The usage of short electrical pulses of the duration of 10 ns allowed to avoid an influence of a self-heating of the investigated structures on current-voltage characteristics. It is shown that the temperature dependence of conductivity is described by the power function G∝Tα. At helium temperatures the asymptotic dependence of current on applied voltage is close to J∝V1+α with α = 0.45. From comparison of the obtained results of measurements with calculations, it is shown that the conductivity of nanotube bundles is well described within the theory of the Luttinger-liquid conductivity for one-dimensional conductors. The self-heating of the carbon nanotube bundles was observed in the case of measurements in the regime of dc current. A method for determination of the self-heating temperature of nanotube bundles as a function of an applied electrical field is proposed. The power dependence of the self-heating temperature on voltage T∝Vp with the exponent p = 2.1 was observed above some threshold voltage in the temperature range 4.2–200 K. Above 200 K the exponent decreased down to p = 1.35.