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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

When an atom is in an excited state, after some amount of time, it will decayto a lower energy state emitting a photon in the process. This is known asspontaneous emission. It is one of the three elementary light-matterinteractions. If it has not decayed at time $t$, then the probability that itdoes so in the next infinitesimal time step $[t, t+\delta t]$, is$t$-independent. So there is no preferred time at which to decay -- in thissense it is a random process. Here we show, by carefully engineering thislight-matter interaction, that we can associate it with a clock, where thematter constitutes the clockwork and the spontaneous emission constitutes theticking of the clock. In particular, we show how to realise the quasi-idealclock. Said clock has been proven -- in an abstract and theoretic sense -- tobe the most accurate clock permissible by quantum theory, with a polynomialenhancement in precision over the best stochastic clock of the same size. Ourresults thus demonstrate that the seemingly random process of spontaneousemission can in actual fact, under the right circumstances, be the most regularone permissible by quantum theory. To achieve this we use geometric featuresand flux-loop insertions to induce symmetry and Berry phases into thelight-matter coupling. We also study the entropy the clock produces per tickand show that it also possesses a quantum advantage over that generated fromthe previously known semi-classical clocks in the literature.

Quantum advantages in timekeeping: dimensional advantage, entropic  advantage and how to realise them via Berry phases and ultra-regular  spontaneous emission