Spontaneous emission from a Wigner crystal

Spontaneous emission from a quasi-two-dimensional Wigner crystal is discuss ed from the quantum-mechanical point of view. We go beyond the dipole appro ximation and take into account the change in electron position during the d e-excitation process. This effect becomes important for the perpendicular e lectron transition. The results derived for the excitation decay rate indic ate (i) a very long electromagnetic lifetime of the first perpendicular exc ited state and (ii) a significant correction in comparison with the result obtained in the standard dipole theory. (C) 2000 Elsevier Science B.V. All rights reserved.