The correct treatment of the close-to-boson character of excitons is known tobe a major problem. In a previous work, we have proposed a ``commutationtechnique'' to include this close-to-boson character in their interactions. Wehere extend this technique to excitons with spin degrees of freedom as they areof crucial importance for many physical effects. Although the exciton totalangular momentum may appear rather appealing at first, we show that theelectron and hole angular momenta are much more appropriate when dealing withscattering processes. As an application of this commutation technique to aspecific problem, we reconsider a previous calculation of the exciton-excitonscattering rate and show that the proposed quantity is intrinsically incorrectfor fundamental reasons linked to the fermionic nature of the excitons.
展开▼
