Dynamics in one-dimensional spin systems

Satoshi Nishimoto

Max Planck Institute for the Physics of Complex Systems

We study the one-dimensional Heisenberg model with an uniform and a staggered magnetic fields, using the dynamical density-matrix renormalization group (DDMRG) technique. In this work, we present the momentum-dependent spin-spin correlarions with the periodic boundary conditions. The DDMRG enables us to investigate the dynamical properties of chain with lengths up to a few hundreds, and the resules are numerically exact in the same sense as %G�%@eexact diagonalization%G�%@fresults are. Thus, we can analyze the low-energy spectrum almost in the thermodynamic limit.