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 show how to generalise the zero temperature Lanczos method for calculatingdynamical correlation functions to finite temperatures. The key is themicrocanonical ensemble, which allows us to replace the involved canonicalensemble with a single appropriately chosen state; in the thermodynamic limitit provides the same physics as the canonical ensemble but with the evaluationof a single expectation value. We can employ the same system sizes as for zerotemperature, but whereas the statistical fluctuations present in small systemsare prohibitive, the spectra of the largest system sizes are surprisinglysmooth. We investigate, as a test case, the spin conductivity of the spin-1/2anisotropic Heisenberg model and in particular we present a comparison ofspectra obtained by the canonical and microcanonical ensemble methods.Comment: 11 pages, 9 figure

Finite-temperature dynamical correlations using the microcanonical ensemble and the Lanczos algorithm