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 develop a time-dependent mean field approach, within the time-dependentvariational principle, to describe the Superfluid-Insulator quantum phasetransition. We construct the zero temperature phase diagram both of theBose-Hubbard model (BHM), and of a spin-S Heisenberg model (SHM) with the XXZanisotropy. The phase diagram of the BHM indicates a phase transition from aMott insulator to a compressibile superfluid phase, and shows the expectedlobe-like structure. The SHM phase diagram displays a quantum phase transitionbetween a paramagnetic and a canted phases showing as well a lobe-likestructure. We show how the BHM and Quantum Phase model (QPM) can be rigorouslyderived from the SHM. Based on such results, the phase boundaries of the SHMare mapped to the BHM ones, while the phase diagram of the QPM is related tothat of the SHM. The QPM's phase diagram obtained through the application ofour approach to the SHM, describes the known onset of the macroscopic phasecoherence from the Coulomb blockade regime for increasing Josephson couplingconstant. The BHM and the QPM phase diagrams are in good agreement with QuantumMonte Carlo results, and with the third order strong coupling perturbativeexpansion.Comment: 15 pages, 8 figures. To be published in Phys. Rev.

Time-dependent mean-field theory of the superfluid-insulator phase transition