Rydberg soft matter

我们周围的世界处于不断变化的状态。物理学家称之为“远离平衡”。远离平衡的系统在自然界中很常见，非平衡动力学在生物自组装和金融市场行为等不同而多样的问题中也会遇到。值得注意的是，尽管物理学是一个非常成熟和先进的领域，但相对而言，它对远离平衡的系统几乎没有什么可说的。在这个建议中，我们将通过利用原子系统来填补这一空白，在原子系统中，我们可以完全控制粒子间的相互作用，但也显示出它们的集体和远离平衡的行为的显着丰富性。我们的原子系统是建立在单个原子的基础上的，我们可以用激光脉冲来控制相互作用，把原子提升到高度激发态，也就是里德伯态。激发到里德伯态的原子系综可以显示复杂的时空动力学，在许多方面类似于软物质系统，如胶体或玻璃。由于具有控制微观相互作用的能力，这种“里德堡软物质”提供了获得微观如何在动力学和结构上决定集体宏观行为的新见解的可能性。里德伯理论的第二个特点是能够控制量子效应的相对重要性。通过研究量子涨落占主导地位的小系统，我们可以探索量子世界和经典世界之间的边界，并研究与宏观纠缠和量子测量问题等基本问题相关的经典事件的量子触发因素。这样的系统也为量子技术的新兴领域提供了相当大的应用潜力。里德伯软物质提供了一个前所未有的机会，可以在当前一些最繁荣的研究领域开辟新天地。然而，重大的进步需要理论和实验之间的密切相互作用。为了解决这个问题，我们组建了一个由理论家和实验家组成的跨学科团队，他们都在英国，但他们的综合专业知识在世界范围内是独一无二的。我们将从发展微观理论开始，它相对简单，容易被实验验证。挑战在于将微观理论扩展到处理许多粒子。在这个阶段，我们需要实验来验证这些近似，并指导理论发展的方向。最后，理论将指导实验回答基本问题和开发潜在的应用。里德伯软物质的新颖性，理论与实验的紧密联系，以及研究人员的独特技能，将使我们能够开拓物理学的新方向，解决基础和应用的关键问题。

The world around us is in a state of constant change. Physicists refer to this as being "far-from-equilibrium". Far-from-equilibrium systems are common throughout nature, and non-equilibrium dynamics is encountered in problems as distinct and varied as biological self-assembly and the behaviour of financial markets. Remarkably, even though physics is a very mature and advanced field, it has comparatively little to say about systems far-from-equilibrium. In this proposal we will help to fill this void by exploiting atomic systems where we have complete control over interparticle interactions, but which also display a remarkable richness in their collective and far-from-equilibrium behaviour. Our atomic system is based on individual atoms where we can control the interactions using laser pulses to promote the atoms to highly excited states known as Rydberg states. An ensemble of atoms excited to Rydberg states can display complex spatial and temporal dynamics that are analogous in many ways to soft matter systems such as colloids or glasses. Due the capability to control microscopic interactions, this "Rydberg soft matter" offers the possibility to gain new insight into how the microscopics determine the collective macroscopic behaviour, both in dynamics and structure. A second special feature of Rydbergs is the ability to control the relative importance of quantum effects. By studying small systems where quantum fluctuations dominate we can probe the boundary between the quantum and classical worlds, and study quantum triggers of classical events which relate to fundamental questions such as macroscopic entanglement and the quantum measurement problem. Such systems also offer considerable potential for applications in the emerging area of quantum technology. Rydberg soft matter offers an unprecedented opportunity to break new ground in some of the most flourishing areas of current research. Significant progress, however, demands a close interplay between theory and experiment. To address this we have assembled an interdisciplinary team of theorists and experimentalists, all based in the UK, but with a combined expertise that is unique worldwide. We will begin by developing the microscopic theory which is relatively straightforward and easily tested by experiment. The challenge comes in extending the microscopic theory to treat many particles. At this stage we need experiments to validate the approximations and guide the direction of the theoretical development. Finally, the theory will guide the experiments to answer fundamental questions and develop potential applications. The novelty of Rydberg soft matter, the close interlinking of theory and experiment, and the unique skill set of the investigators will allow us to pioneer new directions in physics that address key questions both fundamental and applied.