We present a numerically accurate procedure for the study of the electronic structure of one-dimensional incommensurate systems. Our method is used to infer the localized or extended nature of the electronic states by considering, at the same time, both diagonal and off-diagonal matrix elements of an appropriate effective Hamiltonian; we work out a convenient expression of the Lyapunov coefficient in terms of the off-diagonal effective matrix elements. With the further implementation of separately processing (though interdependently) the appropriate segments of the infinite chain, we provide a simple method to reach any desired numerical precision, so that physical aspects can be clearly worked out. Our procedure is tested on an incommensurate potential that exhibits mobility edges.
ELECTRONIC-STRUCTURE IN INCOMMENSURATE POTENTIALS OBTAINED USING A NUMERICALLY ACCURATE RENORMALIZATION SCHEME
GROSSO, GIUSEPPE;
1992
Abstract
We present a numerically accurate procedure for the study of the electronic structure of one-dimensional incommensurate systems. Our method is used to infer the localized or extended nature of the electronic states by considering, at the same time, both diagonal and off-diagonal matrix elements of an appropriate effective Hamiltonian; we work out a convenient expression of the Lyapunov coefficient in terms of the off-diagonal effective matrix elements. With the further implementation of separately processing (though interdependently) the appropriate segments of the infinite chain, we provide a simple method to reach any desired numerical precision, so that physical aspects can be clearly worked out. Our procedure is tested on an incommensurate potential that exhibits mobility edges.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
