We exploit a prescription to observe directly the physical properties of the thermodynamic limit in a continuously applied field in one-dimensional quantum finite lattice systems. By systematically scaling down the energy of the Hamiltonian of the open system from center toward both ends, one could adopt the edge sites with a negligibly small energy scale as the grand canonical small particle bath, and equilibrium states with noninteger arbitrary conserved numbers, e.g., electron numbers or s z, are realized in the main part of the system. This will enable the evaluation of response functions under a continuously varying external field in a small lattice without any fine-tuning or scaling of parameters while keeping the standard numerical accuracy. Demonstrations are given on quantum spin systems and on a Hubbard model by the density-matrix renormalization group.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2012 Jul 24|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics