LANDAU MAPPING AND FERMI-LIQUID PARAMETERS OF THE 2-DIMENSIONAL T-J MODEL

An exact-diagonalization technique on small clusters is used to study the momentum distribution function n(k) of the lightly doped t-J model in two dimensions. We find that n(k) can be decomposed into two compo nents with bosonic and fermionic doping dependence. The bosonic compon ent originates from the incoherent motion of holes and has no signific ance for low-energy physics. For the fermionic component we explicitly perform the one-to-one Landau mapping between all low-lying states of the t-J model and those of a system of spin-1/2 quasiparticles and ex tract the quasiparticle dispersion and Landau parameters.