Ergodicity breaking transition in zero dimensions

 

Quantum Sun modelV reviji Physical Review Letters je mladi raziskovalec Jan Šuntajs skupaj z mentorjem dr. Levom Vidmarjem objavil članek z naslovom “Ergodicity breaking transition in zero dimensions“. V njem opiše nekatere osrednje spektralne lastnosti novega tipa faznih prehodov: prehoda med ergodičnim in neergodičnim mnogodelčnim kvantnim stanjem. Navkljub veliki pozornosti, ki so je bili v zadnjem desetletlju v raziskavah kvantnih mnogodelčnih sistemov deležni tovrstni prehodi, obstajajo številna vprašanja o njihovih ključnih lastnostih še naprej odprta. Objavljeno delo se odlikuje predvsem v tem, da v obravnavanem efektivno ničdimnezionalnem fizikalnem modelu pokaže visoko stopnjo ujemanja med analitičnimi napovedmi in rezultati intenzivnih numeričnih simulacij. Omenjeni rezultati tako
predstavljajo temelj za bodoče raziskave neergodičnih faznih prehodov v višjih dimenzijah in hkrati razložijo nekatere ovire pri opisu teh
prehodov v enodimenzionalnih sistemih, na katere je Jan Šuntajs skupaj s sodelavci z IJS in FMF UL opozoril v svojem prejšnjem
odmevnem delu.

An article titled “Ergodicity breaking transition in zero dimensions“, written by our young researcher Jan Šuntajs and dr. Lev Vidmar, was published in Physical Review Letters. The authors describe some of the key spectral properties of a new type of phase transitions: between the ergodic and nonergodic many-body phases of quantum systems. In spite of considerable and ongoing research efforts directed towards a better understanding of such transitions, many important questions related to them still remain open. One of the most important features of the published work relates to a high degree of agreement between the theoretical predictions and results of intensive numerical simulations for the investigated effectively zero-dimensional physical model. As such, the published results can serve as a benchmark for future investigations of ergodicity breaking transitions in higher dimensions while also explaining some of the problems encountered in investigations of one-dimensional systems. Previously, those were the subject of another important work by Jan Šuntajs along with the colleagues from our department and FMF UL.