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arXiv 0912.3261quant-phcond-mat.quant-gas
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光腔中超流气体的Dicke量子相变

The Dicke Quantum Phase Transition with a Superfluid Gas in an Optical Cavity

Kristian Baumann, Christine Guerlin, Ferdinand Brennecke, Tilman Esslinger

摘要:

相变描述了物理系统中状态的突然变化,例如流体和固体之间的转变。量子气体提供了一个机会,建立一个直接的联系之间的实验和通用模型,捕捉基本的物理。描述集体物质-光相互作用的一个基本概念是Dicke模型,该模型被预测显示出有趣的量子相变。在一个由玻色-爱因斯坦凝聚体耦合到光腔中形成的开放系统中,我们实现了Dicke量子相变,并观察到自组织超固相的出现.相变是由凝聚原子之间的无限长程相互作用驱动的。这些是由涉及腔模和泵浦场的双光子过程引起的。我们表明,超固态的相变可用迪克汉密尔顿量来描述,包括反旋转耦合项,并且超固态相与自发破缺的空间对称性有关。的相变的边界映射出与迪克模型定量协议。这项工作开辟了具有长程相互作用的量子气体领域,并提供了获得新量子相的途径。

英文摘要:

A phase transition describes the sudden change of state in a physical system, such as the transition between a fluid and a solid. Quantum gases provide the opportunity to establish a direct link between experiment and generic models which capture the underlying physics. A fundamental concept to describe the collective matter-light interaction is the Dicke model which has been predicted to show an intriguing quantum phase transition. Here we realize the Dicke quantum phase transition in an open system formed by a Bose-Einstein condensate coupled to an optical cavity, and observe the emergence of a self-organized supersolid phase. The phase transition is driven by infinitely long-ranged interactions between the condensed atoms. These are induced by two-photon processes involving the cavity mode and a pump field. We show that the phase transition is described by the Dicke Hamiltonian, including counter-rotating coupling terms, and that the supersolid phase is associated with a spontaneously broken spatial symmetry. The boundary of the phase transition is mapped out in quantitative agreement with the Dicke model. The work opens the field of quantum gases with long-ranged interactions, and provides access to novel quantum phases.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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