Dynamical singlets and correlation-assisted Peierls transition in VO2.
A theory of the metal-insulator transition in vanadium dioxide from the high- temperature rutile to the low- temperature monoclinic phase is proposed on the basis of cluster dynamical mean-field theory, in conjunction with the density functional scheme. The interplay of strong electronic Coulomb interactions and structural distortions, in particular, the dimerization of vanadium atoms in the low-temperature phase, plays a crucial role. We find that VO2 is not a conventional Mott insulator, but that the formation of dynamical V-V singlet pairs due to strong Coulomb correlations is necessary to trigger the opening of a Peierls gap.
Biermann
S
S
Centre de Physique Théorique, Ecole Polytechnique, 91128 Palaiseau Cedex, France.
Poteryaev
A
A
Lichtenstein
A I
AI
Georges
A
A