Artículos de revistas
Modulation of charge-density waves by superlattice structures
Fecha
2006-05-31Registro en:
Physical Review B - Condensed Matter and Materials Physics, v. 73, n. 19, 2006.
1098-0121
1550-235X
10.1103/PhysRevB.73.193407
2-s2.0-33646866606
Autor
Universidade Estadual Paulista (UNESP)
Universidade Federal do Rio de Janeiro (UFRJ)
Institución
Resumen
We discuss the interplay between electronic correlations and an underlying superlattice structure in determining the period of charge density waves (CDW's), by considering a one-dimensional Hubbard model with a repeated (nonrandom) pattern of repulsive (U>0) and free (U=0) sites. Density matrix renormalization group diagonalization of finite systems (up to 120 sites) is used to calculate the charge-density correlation function and structure factor in the ground state. The modulation period can still be predicted through effective Fermi wave vectors kF* and densities, and we have found that it is much more sensitive to electron (or hole) doping, both because of the narrow range of densities needed to go from q* =0 to π, but also due to sharp 2 kF* -4 kF* transitions; these features render CDW's more versatile for actual applications in heterostructures than in homogeneous systems. © 2006 The American Physical Society.