K. Guven et al., Band-gap renormalization in quantum wire systems: dynamical correlations and multi-subband effects, J PHYS-COND, 12(9), 2000, pp. 2031-2042
We study the band-gap renormalization in a model semiconductor quantum wire
due to the exchange-correlation effects among the charge carriers. We cons
truct a two-subband model for the quantum wire, and employ the GW-approxima
tion to obtain the renormalized quasi-particle energies at the optical band
edge. The renormalization is calculated as a function of electron-hole pla
sma density and the wire radius. Our results show that the very presence of
the second subband affects the renormalization process even in the absence
of occupation by the carriers. We compare the fully dynamical random-phase
approximation results to the quasi-static case in order to emphasize the d
ynamical correlation effects. Effects of electron-phonon interaction within
the two-subband model are also considered.