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 point out that in the first order time-dependent perturbation theory, thetransition probability may behave nonsmoothly in time and have kinksperiodically. Moreover, the detailed temporal evolution can be sensitive to theexact locations of the eigenvalues in the continuum spectrum, in contrast tocoarse-graining ideas. Underlying this nonsmooth and level-resolved dynamics isa simple equality about the sinc function $\sinc x \equiv \sin x / x$. Thesephysical effects appear in many systems with approximately equally spacedspectra, and is also robust for larger-amplitude coupling beyond the domain ofperturbation theory. We use a one-dimensional periodically driven tight-bindingmodel to illustrate these effects, both within and outside the perturbativeregime.

Nonsmooth and level-resolved dynamics illustrated with the tight binding model