Real-Time Ab Initio Simulations of Excited Carrier Dynamics in Carbon Nanotubes

Physical Review Letters 97, 126104 - 4 (2006)

Real-Time Ab Initio Simulations of Excited Carrier Dynamics in Carbon Nanotubes

Y. Miyamoto, A. Rubio, D. Tománek

Combining time-dependent density functional calculations for electrons with molecular dynamics simulations for ions, we investigate the dynamics of excited carriers in a (3,3) carbon nanotube at different temperatures. Following an hv = 6.8 eV photoexcitation, the carrier decay is initially dominated by efficient coupling to electronic degrees of freedom. At room temperature, the excitation gap is reduced to nearly half its initial value after ~ 230 fs, where coupling to ionic motion starts dominating the decay. We show that the onset point and damping rate in the phonon regime change with initial ion velocities, a manifestation of temperature-dependent coupling between electronic and ionic degrees of freedom. Auxilary material EPAPS

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http://dx.doi.org/10.1103/PhysRevLett.97.126104

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