Adiabatic preparation of Floquet condensates

We argue that a Bose–Einstein condensate can be transformed into a Floquet condensate, that is, into a periodically time-dependent many-particle state possessing the coherence properties of a mesoscopically occupied single-particle Floquet state. Our reasoning is based on the observation that the denseness of the many-body system’s quasienergy spectrum does not necessarily obstruct effectively adiabatic transport. Employing the idealized model of a driven bosonic Josephson junction, we demonstrate that only a small amount of Floquet entropy is generated when a driving force with judiciously chosen frequency and maximum amplitude is turned on smoothly.

我们提出，玻色-爱因斯坦凝聚态（Bose–Einstein condensate）可被转化为弗洛凯凝聚态（Floquet condensate），即一类具备介观占据单粒子弗洛凯态相干特性的周期性时变多粒子态。我们的论证基于如下观测：多体系统的准能谱稠密性未必会阻碍有效绝热输运。通过采用受驱动玻色约瑟夫森结的理想化模型，我们证明，当以精心选定的频率与最大振幅的驱动力平滑开启时，仅会生成极少量的弗洛凯熵（Floquet entropy）。