Abstract
We consider noninteracting fermions on a lattice and give a general result for the reduced density matrices corresponding to parts of the system. This allows to calculate their spectra, which are essential in the density-matrix renormalization group method, by diagonalizing small matrices. We discuss these spectra and their typical features for various fermionic quantum chains and for the two-dimensional tight-binding model.
- Received 14 March 2001
DOI:https://doi.org/10.1103/PhysRevB.64.064412
©2001 American Physical Society
