A. Nandgaonkar et al., NUMERICAL SIMULATIONS OF STRONGLY CORRELATED SYSTEMS - AN IMPURITY INONE-DIMENSION, Indian Journal of Pure & Applied Physics, 35(11), 1997, pp. 665-673
The ground state properties of a single substitutional impurity in a s
trongly correlated host are studied using exact diagonalisation. Stron
gly interacting electrons are modeled by a repulsive Hubbard model. Bo
th magnetic and non-magnetic impurities have been studied. Ic is obser
ved that the local moment phase on the impurity is stabilized due to r
epulsive interactions amongst the electrons. A scalar impurity (either
with a double occupancy or a static vacancy) is seen to induce a loca
l moment on the neighbouring sites for fillings close to half filling.
Static spin and charge correlation functions reflect a non-Fermi liqu
id character for both kinds of impurities, scalar and magnetic. A comp
lete healing of the chain in presence of a magnetic impurity is seen a
t half filling. Away from half filling, such healing is seen only in t
he spin sector. Finally, we observe that the static spin and charge co
rrelation functions for a magnetic impurity and a static vacancy are i
dentical at quarter filling.