权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Quantum states in ultracold fermionic gases in optical lattices:Supersolid and dynamically generated antiferromagnetic states

光学晶格中超冷费米子气体的量子态：超固体和动态生成的反铁磁态

基本信息

批准号：
197868533
负责人：
Dr. Johannes Bauer
金额：
--
依托单位：
Department of Physics
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2011
资助国家：
德国
起止时间：
2010-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/197868533?language=en
关键词：
Quantum states ultracold fermionic gases

项目摘要

In recent years the fields of condensed matter physics and ultracold atomic gas physics have developed a fruitful interplay. The former has a long history of describing quantum states of matter based on simplified models, such as the Hubbard model, whilst the latter now manages to simulate these models and generate exciting quantum states. The twofold objective of the research project is to better understand the stability of the supersolid quantum state and the dynamic generation of antiferromagnetic (AF) quantum states. The supersolid state of matter, a peculiar state with simultaneous crystalline order and superfluid properties, has been proposed to be realizable in a gas of attractive fermions confined to an optical lattice. The research project will theoretically model such a state and analyze its stability. This will be achieved by real space dynamical mean field calculations utilizing the numerical renormalization group as an impurity solver. The second part deals with a correlated fermionic system, which by an interaction quench is driven into situation where a strong AF instability is present. Using the Hubbard model, we will develop and apply non-equilibrium techniques to understand the resulting behavior. A realization of this non-equilibrium situation is possible for an ultracold gas of fermions in an optical lattice with commensurate filling, which is tuned suddenly to the strongly repulsive side of a Feshbach resonance. There, the AF instability competes with processes of molecule formation, which can also occur on this side of the Feshbach resonance. By taking into account both processes we will investigate theoretically the time-dependent response of the system and predict its dominant behavior. Current experiments are performed in regimes very close to the situations described here. The expected experimental realizations within the next years make it a timely and highly relevant research project.

近年来，凝聚态物理学和超冷原子气体物理学的领域已经发展出了富有成效的相互作用。前者在基于简化模型（如哈伯德模型）描述物质的量子态方面有着悠久的历史，而后者现在设法模拟这些模型并生成令人兴奋的量子态。该研究项目的双重目标是更好地理解超固体量子态的稳定性和反铁磁（AF）量子态的动态生成。物质的超固态是一种同时具有晶体有序性和超流体性质的特殊状态，已经被提出可以在被限制在光学晶格中的有吸引力的费米子气体中实现。该研究项目将从理论上模拟这种状态并分析其稳定性。这将通过利用数值重整化群作为杂质求解器的真实的空间动力学平均场计算来实现。第二部分讨论了一个关联费米子系统，它被相互作用淬灭而进入一个强AF不稳定性的状态。使用哈伯德模型，我们将开发和应用非平衡技术来理解由此产生的行为。实现这种非平衡的情况是可能的超冷气体的费米子在一个光学晶格与相称的填充，这是突然调谐到强烈排斥的一方的Feshbach共振。在那里，AF不稳定性与分子形成过程竞争，这也可能发生在费什巴赫共振的这一侧。通过考虑这两个过程，我们将从理论上研究系统的时间依赖性响应，并预测其主导行为。目前的实验是在非常接近这里描述的情况下进行的。预计在未来几年内实现的实验使其成为一个及时和高度相关的研究项目。