6 research outputs found
The Role of Boundary Conditions in the Real-Space Renormalization Group
We show that the failure of the real-space RG method in the 1D tight-binding
model is not intrinsic to the method as considered so far but depends on the
choice of boundary conditions. For fixed BC's the failure does happen. For free
BC's we present a new analytical block RG-method which gives the exact ground
state of the model and the correct -law for the energy of the first
excited state in the large (size)-limit. We also give a reconstruction
method for the wave-functions of the excited states.Comment: LATEX file, 12 pages, 5 figures available upon reques