Pronounced electron-phonon interactions in ultraclean suspended carbon nanotubes

Article

关键词: BORN-OPPENHEIMER APPROXIMATION;    SINGLE;    SCATTERING;    TRANSPORT;    BREAKDOWN;   

DOI  :  10.1103/PhysRevB.86.045427

来源: SCIE

【 摘 要 】

We report pronounced electron-phonon interactions in suspended, nearly defect-freemetallic carbon nanotubes, observed through a Kohn anomaly (KA) of greater strength than theoretically predicted. This KA is accompanied by a gate-induced modulation of the G_band Raman intensity. By establishing a quantitative correlation between the strength of the nonadiabatic KA and the modulation of Raman intensity, we determine that the underlying cause that leads to both these effects is the same. By varying temperature, we find that metallic nanotubes can switch between a regime in which the nonadiabatic KA is clearly observed and a regime where the nonadiabatic KA is absent. The regime that does not exhibit a nonadiabatic KA is accompanied by a suppression of the Raman intensity under electrostatic gating, whereas in the regime where the nonadiabatic KA is clearly observed, strong enhancement of the Raman intensity with gating is observed.

【 授权许可】

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