English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The influence of short-range Coulomb correlations on the Mott transition inthe single-band Hubbard model at half-filling is studied within cellulardynamical mean field theory for square and triangular lattices.Finite-temperature exact diagonalization is used to investigate correlationswithin two-, three-, and four-site clusters. Transforming the non-localself-energy from a site basis to a molecular orbital basis, we focus on theinter-orbital charge transfer between these cluster molecular orbitals in thevicinity of the Mott transition. In all cases studied, the charge transfer isfound to be small, indicating weak Coulomb induced orbital polarization despitesizable level splitting between orbitals. These results demonstrate that allcluster molecular orbitals take part in the Mott transition and that theinsulating gap opens simultaneously across the entire Fermi surface. Thus, athalf-filling we do not find orbital-selective Mott transitions, nor acombination of band filling and Mott transition in different orbitals.Nevertheless, the approach towards the transition differs greatly betweencluster orbitals, giving rise to a pronounced momentum variation along theFermi surface, in agreement with previous works. The near absence of Coulombinduced orbital polarization in these clusters differs qualitatively fromsingle-site multi-orbital studies of several transition metal oxides, where theMott phase exhibits nearly complete orbital polarization as a result of acorrelation driven enhancement of the crystal field splitting. The strongsingle-particle coupling among cluster orbitals in the single-band case isidentified as the source of this difference.

Multisite versus multiorbital Coulomb correlations studied within finite-temperature exact diagonalization dynamical mean-field theory