Field-theoretic Hamiltonian approach H()=[d3xSm.091(x1) LLL is Lagrangian at 1=o0 OL 0(n/O) Omitting the retardation effect, the Hamiltonia n is H=d' xv(xirV+ M)v(x) +2∑dd((m7w0 1=o丌 May 9, 2013@ USTCMay 9, 2013 @ USTC Field-theoretic Hamiltonian approach     = = +     = −  +      =         −   =            i i i i i i i d x d x x x x x x x i M x t L L t x t H t d x ( ) ( ) (1,2) ( ) ( ) 2 1 H d ( )( γ ) ( ) Omitting the retardation effect, the Hamiltonia n is ( / ) , L is Lagrangian, ( , ) ( ) 3 3 3 3