AC-driven Quantum Phase Transitions

交流驱动的量子相变

• 批准号: 235452962
• 负责人: Privatdozent Dr. Gernot Schaller, since 4/2017
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/235452962?language=en
• 关键词: AC; driven; Quantum; Phase; Transitions

A quantum phase transition is a drastic change of state of a many-body system which occurs at zero temperature. Relatively little is known about such critical behaviour under nonequilibrium conditions, which in this project will be generated by periodic fields (`AC-driving'). Our key objectives are- to theoretically formulate, analyse, and interpret AC-driven quantum phase transitions. - to investigate the existence of novel states of matter under the effect of a nonadiabatic monochromatic driving with no analogues in static systems.- to apply established analytical and numerical methods in order to describe AC-driven critical behavior for so far unexplored models. - to explore the use of new theoretical methods, such as an effective partition function and the geometrical phase (Berry phase), in order to analyse critical phenomena under nonequilibrium conditions.- to discuss the relevance of the results for recent state-of-the-art experiments such as Bose-Einstein condensates in optical cavities.

量子相变是发生在零温度下的多体系统状态的剧烈变化。相对而言，人们对非平衡条件下的这种临界行为知之甚少，在这个项目中，这种临界行为将由周期场（“交流驱动”）产生。我们的主要目标是-理论上制定，分析和解释交流驱动的量子相变。-研究在非绝热单色驱动作用下，在静态系统中没有类似物的物质新状态的存在。-应用已建立的分析和数值方法，以描述迄今尚未开发的模型的交流驱动临界行为。-探索使用新的理论方法，如有效配分函数和几何相（贝里相），以分析非平衡条件下的临界现象。-讨论最近最先进的实验结果的相关性，如光学腔中的玻色-爱因斯坦凝聚体。

项目成果

Random-walk topological transition revealed via electron counting

• DOI: 10.1103/physrevb.96.241404
• 发表时间: 2017-12-08
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Engelhardt, G.;Benito, M.;Brandes, T.
• 通讯作者: Brandes, T.

Excited-state quantum phase transitions and periodic dynamics

• DOI: 10.1103/physreva.91.013631
• 发表时间: 2015-01-30
• 期刊: PHYSICAL REVIEW A
• 影响因子: 2.9
• 作者: Engelhardt, G.;Bastidas, V. M.;Brandes, T.
• 通讯作者: Brandes, T.

From quantum heat engines to laser cooling: Floquet theory beyond the Born–Markov approximation

• DOI: 10.1088/1367-2630/aac583
• 发表时间: 2017-12
• 期刊: New Journal of Physics
• 影响因子: 3.3
• 作者: S. Restrepo;J. Cerrillo;P. Strasberg;G. Schaller

Quantum criticality and dynamical instability in the kicked-top model.

• DOI: 10.1103/physrevlett.112.140408
• 发表时间: 2013-08
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: V. Bastidas;P. Pérez‐Fernández;M. Vogl;T. Brandes