Incommensurate magnetic fluctuations in the underdoped Copper Oxide Materials

[[abstract]]The doping dependence of magnetic fluctuations in the underdopcd copper oxide materials are studied within the t-J model. It is shown that away from the half-filling, the magnetic Bragg peaks from the dynamical spin structure factor spectrum S(k,ω) are incommensurate with the lattice. Although the incommensurability δ(cursive Greek chi) is almost energy-independent, the dynamical spin susceptibility χ″(k,ω) at the incommensurate wave vectors is changed dramatically with energies, which is consistent with the experiments.[[notice]]補正完畢[[journaltype]]國