invited by Cyrille BARRETEAU
A quasi-1D conductor can be built using a hydrogen passivated silicon surface by desorbing H atoms in a row with the help of an STM tip. The row of dangling bonds plays the role of an atomic-scale wire at the surface, and a current can flow through it. What happens if the electrons heat it up? Calculating the electronic transport properties taking into account the interaction with the nuclei is a central question. A time-dependent calculation is presented based on the mixed classical/quantum Ehrenfest approximation. Treating the electron quantum mechanically and the oscillators classically, the ion dynamics will be discussed. One can also think of a model in which the vibrational degree of freedom is quantified and the electron is treated just in the same way as previously. In this case, it will be shown that the probability to excite the vibration is triggered by the motion of the electronic wave-packet propagating through the system. With the help of a simple model hamiltonian, it is shown that there is a condition to fulfill for the transition to occur.
CEMES, Groupe nanosciences