Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2005-12-23
Physical Review Letters 96, 046410 (2006); 4 pages
Physics
Condensed Matter
Strongly Correlated Electrons
10 pages, 4 figures
Scientific paper
10.1103/PhysRevLett.96.046410
The compound LiAl_yTi_(2-y)O_4 undergoes a metal-to-insulator transition for y_c ~0 .33. This system, in the absence of strong electronic correlations, is a prototypical example of quantum site percolation. However, it is known that the effects of disorder produced by such a percolating lattice are insufficient to explain this transition: a quantum site percolation model predicts y_c ~ 0.8, well above the experimental value. We have included an on-site Hubbard interaction into a model of this compound, using a real-space Hartree-Fock approach, and have found that for a Hubbard energy equal to 1.5 times the non-interacting bandwidth one obtains y_c~0.35. Further, as a function of increasing Hubbard energy, we find that an Altshuler-Aronov suppression of the density of states, delta N(E) ~ sqrt(| E-E_F |), reduces the density of states at the Fermi energy to zero at the critical Hubbard interaction. Using this ratio of correlation to hopping energy one is led to a prediction for the value of near-neighbour superexchange J/t~1/3 which is similar to that for the cuprate superconductors.
Atkinson W. A.
Fazileh F.
Gooding R. J.
Johnston David C.
No associations
LandOfFree
The role of strong electronic correlations in the metal-to-insulator transition in disordered LiAl_yTi_(2-y)O_4 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The role of strong electronic correlations in the metal-to-insulator transition in disordered LiAl_yTi_(2-y)O_4, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The role of strong electronic correlations in the metal-to-insulator transition in disordered LiAl_yTi_(2-y)O_4 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-696783