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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We derive expressions for the zeroth and the first three spectral moment sumrules for the retarded Green's function and for the zeroth and the firstspectral moment sum rules for the retarded self-energy of the inhomogeneousBose-Hubbard model in nonequilibrium, when the local on-site repulsion and thechemical potential are time-dependent, and in the presence of an externaltime-dependent electromagnetic field. We also evaluate these moments forequilibrium, where all time dependence and external fields vanish. Unlikesimilar sum rules for the Fermi-Hubbard model, in the Bose-Hubbard model case,the sum rules often depend on expectation values that cannot be determinedsimply from parameters in the Hamiltonian like the interaction strength andchemical potential, but require knowledge of equal time many-body expectationvalues from some other source. We show how one can approximately evaluate theseexpectation values for the Mott-insulating phase in a systematicstrong-coupling expansion in powers of the hopping divided by the interaction.We compare the exact moments to moments of spectral functions calculated from avariety of different approximations and use them to benchmark their accuracy.

physical review. a, atomic, molecular, and optical physics/physical review, a, atomic, molecular, and optical physics

Spectral moment sum rules for the retarded Green's function and  self-energy of the inhomogeneous Bose-Hubbard model in equilibrium and  nonequilibrium