Small-polaron behaviour in a two-dimensional honeycomb net is studied by applying the strong-coupling perturbative method to the Holstein molecular crystal model. We find that small optical polarons can be mobile also if the electrons are strongly coupled to the lattice. Before the polarons localize and become very heavy, there is in fact a window of electron-phonon couplings in which the polarons are small and have masses of order simeq5-50 times the bare band mass according to the value of the adiabaticity parameter. The two-dimensional honeycomb net favours the mobility of small optical polarons, in comparison with the square lattice.
Polaron Self-Trapping in a Honeycomb Net
ZOLI, Marco
2001-01-01
Abstract
Small-polaron behaviour in a two-dimensional honeycomb net is studied by applying the strong-coupling perturbative method to the Holstein molecular crystal model. We find that small optical polarons can be mobile also if the electrons are strongly coupled to the lattice. Before the polarons localize and become very heavy, there is in fact a window of electron-phonon couplings in which the polarons are small and have masses of order simeq5-50 times the bare band mass according to the value of the adiabaticity parameter. The two-dimensional honeycomb net favours the mobility of small optical polarons, in comparison with the square lattice.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
