Electron-phonon coupling in single-walled carbon nanotubes determined by shot noise

Abstract

We have measured shot noise in metallic single-walled carbon nanotubes of length L=1 μm and have found strong suppression of noise with increasing voltage. We conclude that the coupling of electron and phonon baths at temperatures Te and Tph is described at intermediate bias (20 mV<Vds≲200 mV) by heat flow equation P=ΣL(T3e−T3ph), where Σ∼3×10 exp −9 W/m K exp 3 due to electron interaction with acoustic phonons, while at higher voltages optical phonon-electron interaction leads to P=κopL[N(Te)−N(Tph)], where N(T)=1/[exp(ℏΩ/kBT)−1] with optical phonon energy ℏΩ and κop=2×10 exp 2 W/m.