Interaction-induced Landau-Zener transitions
2014 (English)In: Europhysics letters, ISSN 0295-5075, E-ISSN 1286-4854, Vol. 107, no 3, 30007- p.Article in journal (Refereed) Published
By considering a quantum-critical Lipkin-Meshkov-Glick model we analyze a new type of Landau-Zener transitions where the population transfer is mediated by interaction rather than from a direct diabatic coupling. For this scenario, at a mean-field level the dynamics is greatly influenced by quantum interferences. In particular, regardless of how slow the Landau-Zener sweep is, for certain parameters almost no population transfer occurs, which is in stark contrast to the regular Landau-Zener model. For moderate system sizes, this counterintuitive mean-field behaviour is not duplicated in the quantum case. This can be attributed to quantum fluctuations and to the fact that multi-level Landau-Zener-Stuckelberg interferences have a dephasing effect on the above-mentioned phenomenon. We also find a discrepancy between the quantum and mean-field models in terms of how the transfer probabilities scale with the sweep velocity.
Place, publisher, year, edition, pages
2014. Vol. 107, no 3, 30007- p.
IdentifiersURN: urn:nbn:se:su:diva-107627DOI: 10.1209/0295-5075/107/30007ISI: 000340780100007OAI: oai:DiVA.org:su-107627DiVA: diva2:748983