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

We consider fermions in one-dimensional superlattices (SL's), modeled bysite-dependent Hubbard-U couplings arranged in a repeated pattern of repulsive(i.e., U>0) and free (U=0) sites. Density Matrix Renormalization Group (DMRG)diagonalization of finite systems is used to calculate the local moment and themagnetic structure factor in the ground state. We have found four regimes formagnetic behavior: uniform local moments forming a spin-density wave (SDW),`floppy' local moments with short-ranged correlations, local moments onrepulsive sites forming long-period SDW's superimposed with short-rangedcorrelations, and local moments on repulsive sites solely with long-periodSDW's; the boundaries between these regimes depend on the range of electronicdensities, rho, and on the SL aspect ratio. Above a critical electronicdensity, rho_{uparrow downarrow}, the SDW period oscillates both with rho andwith the spacer thickness. The former oscillation allows one to reproduce allSDW wave vectors within a small range of electronic densities, unlike thehomogeneous system. The latter oscillation is related to the exchangeoscillation observed in magnetic multilayers. A crossover between regimes of`thin' to `thick' layers has also been observed.Comment: 9 two-column pages, 10 figure

Multiperiodic magnetic structures in Hubbard superlattices