The current-voltage curve of metallic carbon nanotubes (CNTs) displays at high bias a sudden increase of the resistivity due to the scattering of electrons with phonons having an anomalously high population (hot phonons). Here, we show that it is possible to improve the electrical performances of metallic CNTs by ${}^{13}\mathrm{C}$ isotope enrichment. In fact, isotopic disorder creates additional channels for the hot-phonon deexcitation, reduces their population and, thus, the nanotube high-bias differential resistance. This is an extraordinary case where disorder improves the electronic transport.

• Received 7 July 2008

DOI:https://doi.org/10.1103/PhysRevLett.102.196801