发表机构
Institute of Science and Technology Austria (ISTA); Pitaevskii BEC Center, CNR-INO and Dipartimento di Fisica, Università di Trento; Trento Institute for Fundamental Physics and Applications, INFN; Department of Physics and Astronomy, Aarhus University（奥地利科学与技术研究院; 特伦托大学物理系、意大利国家研究委员会光学研究所皮塔耶夫斯基玻色-爱因斯坦凝聚中心; 特伦托基础物理与应用研究所，意大利国家核物理研究所; 奥胡斯大学物理与天文学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过量子古茨维勒多模变分法，统一描述二维玻色-哈伯德模型中杂质形成的极化子，揭示临界区强关联导致的非解析特征及非平衡动力学，为强关联玻色浴传感提供可观测预测。
AI 中文摘要
一个浸入量子简并气体中的可移动杂质粒子会导致准粒子的形成，该准粒子可作为其环境的传感器。在此，我们发展了一个统一波函数描述，用于描述二维玻色-哈伯德模型中跨越莫特绝缘体到超流体转变的杂质。基于量子古茨维勒方法的多模变分拟设，我们展示了杂质可以形成多种极化子和分子态。除了它们的谱性质外，波函数还直接提供了这些态的微观结构信息，并且我们证明了量子相变临界区域中的强关联会导致极化子性质出现多个非解析特征。增加杂质-玻色子相互作用会导致极化子与分子基态之间的转变，并且在量子临界点处，随着浴模式软化，杂质缀饰云中的玻色子数量迅速增长。我们进一步揭示了在玻色-哈伯德模型不同相中注入杂质后，定性上不同的非平衡多体动力学。我们的谱、实空间和动力学预测描述了强关联玻色子浴中极化子的互补性质，这些性质可以利用当前的光学晶格中原子的技术进行观测。
英文摘要
A mobile impurity particle immersed in a quantum degenerate gas leads to the formation of a quasiparticle, which can serve as a sensor for its environment. Here, we develop a unified wave function description of an impurity in a two-dimensional Bose-Hubbard model across the Mott-insulator to superfluid transition. Using a multi-mode variational ansatz based on the quantum Gutzwiller approach, we show that the impurity can form several kinds of polaronic and molecular states. In addition to their spectral properties, the wave function provides direct access to the microscopic structure of these states, and we demonstrate that strong correlations in the critical regime of the quantum phase transition give rise to several non-analytic features in the polaron properties. Increasing the impurity-boson interaction leads to transitions between polaron and molecular ground states, and the number of bosons in the impurity dressing cloud grows rapidly at the quantum critical point as the bath modes soften. We furthermore reveal qualitatively distinct non-equilibrium many-body dynamics after the injection of the impurity in the different phases of the Bose-Hubbard model. Our spectral, real space, and dynamical predictions describe complementary properties of polarons in a strongly correlated bosonic bath, which can be observed using current techniques with atoms in optical lattices.
