Dynamical mean-field study of the Mott transition in thin films

Abstract

The correlation-driven transition from a paramagnetic metal to a paramagnetic Mott-Hubbard insulator is studied within the half-filled Hubbard model for a thin-film geometry. We consider simple-cubic films with different low-index surfaces and film thickness d ranging from d=1 (two-dimensional) up to d=8. Using the dynamical mean-field theory, the lattice (film) problem is self-consistently mapped onto a set of d single-impurity Anderson models which are indirectly coupled via the respective baths of conduction electrons. The impurity models are solved at zero temperature using the exact-diagonalization algorithm. We investigate the layer and thickness dependence of the electronic structure in the low-energy regime. Effects due to the finite film thickness are found to be the more pronounced the lower is the film-surface coordination number. For the comparatively open sc(111) geometry we find a strong layer dependence of the quasi-particle weight while it is much less pronounced for the sc(110) and the sc(100) film geometries. For a given geometry and thickness d there is a unique critical interaction strength Uc2(d) at which all effective masses diverge and there is a unique strength Uc1(d) where the insulating solution disappears. Uc2(d) and Uc1(d) gradually increase with increasing thickness eventually approaching their bulk values. A simple analytical argument explains the complete geometry and thickness dependence of Uc2. Uc1 is found to scale linearly with Uc2.

LaTeX, 17 pages, 15 eps figures included, Eur. Phys. J. B (in press)

Cited by in corpus (23)

• Electronic Structure Calculations with Dynamical Mean-Field Theory: A Spectral Density Functional Approach
• Metallic surface of a Mott insulator - Mott insulating surface of a metal
• Two-site dynamical mean-field theory
• One-dimensional metallic behavior of the stripe phase in La${}_{2-x}$Sr${}_x$CuO${}_4$
• Mott transitions in correlated electron systems with orbital degrees of freedom
• From Mott Insulator to Band Insulator: A DMFT Study
• Mottness collapse without metallisation in the domain walls of triangular-lattice Mott insulator 1T-TaS${}_2$
• Van Hove singularities in the paramagnetic phase of the Hubbard model: a DMFT study
• Correlation and surface effects in Vanadium Oxides
• Dynamically generated edge states in topological Kondo insulators
• Self-energy-functional theory for systems of interacting electrons with disorder
• Dynamical mean-field theory of indirect magnetic exchange
• Electrical conductivity in the Hubbard model: orbital effects of magnetic field
• Anisotropy of electronic correlations: On the applicability of local theories to layered materials
• Influence of static disorder and polaronic band formation on interfacial electron transfer in organic photovoltaic devices
• Charge redistribution in correlated heterostuctures within nonequilibrium real-space dynamical mean-field theory
• Influence of uncorrelated overlayers on the magnetism in thin itinerant-electron films
• Spectral changes in layered $f$-electron systems induced by Kondo hole substitution in the boundary-layer
• Resonance Effects in Correlated Multilayer Heterostructures
• Optical conductivity of topological Kondo insulating states
• An electric-field driven Mott metal-insulator transition in correlated thin films: an inhomogeneous dynamical mean-field theory approach
• Inhomogeneous dynamical mean field theory of the small polaron problem
• Photodriven Mott insulating heterostructures: A steady-state study of impact ionization processes