Incidence of the Tomonaga-Luttinger liquid state on the NMR spin-lattice relaxation in carbon nanotubes

¹  Laboratoire de Physique des Solides, Université Paris-Sud 11, CNRS UMR 8502 - 91405 Orsay, France, EU
²  IFW Dresden - P.O. Box 270116, D-01171 Dresden, Germany, EU
³  University of Vienna, Faculty of Physics - Strudlhofgasse 4, A-1090 Wien, Austria, EU
⁴  Budapest University of Technology and Economics, Institute of Physics - H-1521 Budapest, Hungary, EU

Corresponding author: ihara@scphys.kyoto-u.ac.jp

Received: 26 January 2010
Accepted: 29 March 2010

Abstract

We report ¹³C nuclear magnetic resonance measurements on ¹³C-enriched single-wall carbon nanotube (SWCNT) bundles. The temperature dependence of the nuclear spin-lattice relaxation rate, 1/T₁, exhibits a power law variation, as expected for a Tomonaga-Luttinger liquid (TLL). The observed exponent is smaller than that expected for the two-band TLL model. A departure from the power law is observed only at low T, where thermal and electronic Zeeman energy merge. Extrapolation to zero magnetic field indicates gapless spin excitations. The wide T range on which power law behaviour is observed suggests that SWCNT is so far the best realization of a one-dimensional quantum metal.