Department of Mechanical Engineering
Kenneth E. Goodson
Pop, E., Mann, D., Cao, J., Wang, Q., Goodson, K.E., and Dai, H., 2005, "Negative Differential Conductance and Hot Phonons in Suspended Nanotube Molecular Wires," Physical Review Letters, Vol. 95, pp. 155505-155509.
Freely suspended metallic single-walled carbon nanotubes (SWNTs) exhibit reduced current carrying ability compared to those lying on substrates, and striking negative differential conductance at low electric fields. Theoretical analysis reveals significant self-heating effects including electron scattering by hot nonequilibrium optical phonons. Electron transport characteristics under strong self-heating are exploited for the first time to probe the thermal conductivity of individual SWNTs (~3600 Wm-1 K-1 at T=300 K) up to ~700 K, and reveal a 1/T dependence expected for umklapp phonon scattering at high temperatures.