... 2 - 2me 8y~ - 2m" 8y~ - 2f L8Z2 + ~Ye + ~y"e2+eF(Ye - y,, )- I- -, .Ere - rhH =(24)Ham song thii trlplg thai C(Jban cua exciton:\l!(r-;,r-;') = N (P(Ye)1>(y,,)exp{-Alr-; ... :~i(k,CJJ)=~r"(k)-L roo dCJJ'ImVs(q,CJJ:+ib)[l+g(CJJ')-J;(k-q)] 42q J-00 7r CJJ+~b- ei(k - q) + Pi - CJJI . ( )~iX(k) = - L V(q)/;(k - q),q(43)g(CJJ)= ell:-l la ham pMn b6 bosonHam ... : 1.02.011!:):~ ;, H~:rl!-Nt> :-& quot;~\TUE?'\!'r-~' ('1n 1 1 ; ,-, ;", ' it jC. - ,, , I -~ -_ J, -! : A' '" -A'TOM TAT LUhN AN TIEN...