FINESS 2009 (Finite Temperature Non-Equilibrium Superfluid Systems)

超流，或没有粘性的流体流动，是一种本质上的量子力学现象，也就是说，在它发生的地方，它与系统在微观、原子水平上的性质密切相关。然而，超流性与一些壮观的大规模效应有关，最明显的是在液氦II中，在适当的情况下，流体可以沿着墙壁流动，并从封闭容器中流出。超流在各种物理系统中都可以观察到，而且经常与玻色-爱因斯坦凝聚现象密切相关，在玻色-爱因斯坦凝聚中，对于某些类型的相同(玻色子)粒子，在足够低的温度下，相当一部分粒子坍塌成相同的状态，从某种意义上说，就像一个粒子。1995年，埃里克·康奈尔、沃尔夫冈·凯特勒和卡尔·威曼因观察到稀薄原子蒸气中的玻色-爱因斯坦凝聚而获得2001年诺贝尔奖，从而为超流体及其相关性质的基础研究提供了巨大的刺激。这在很大程度上是因为这种稀薄的蒸汽比密度大得多的液氦或金属和陶瓷系统更容易描述和理解，在这些系统中观察到了相关的超导现象。一个更新的相关现象是半导体中的所谓激子和极化子凝聚，人们对这种系统发出的光的性质特别感兴趣。这是一个不断扩大的领域，研究各种超流体和凝聚现象的工作人员来自同样广泛的科学背景。因此，跨学科合作有很大的余地，特别是一些看似不同的理论方法，每一种都有其独特的优势和见解，独立地描述似乎有许多共同之处的系统。这在试图精确描述动力学时(即当系统不再处于平衡状态时)以及当系统温度较低但明显大于绝对零度时尤其适用。对于任何潜在的应用，例如精确测量表面力、时间和频率标准，甚至可能解释超出爱因斯坦广义相对论所描述的引力效应，对非平衡构型中的有限温度的透彻、预测的理解将是必不可少的，也是基本的物理兴趣。因此，我们选择举办研讨会，该研讨会将于2009年9月在达勒姆举行，届时将有一批杰出的国际顶尖科学家。这对英国物理学来说是一个很好的机会，特别是对参加研讨会的该领域的初级工作者来说。

Superfluidity, or fluid flow without viscosity, is an intrinsically quantum-mechanical phenomenon, that is, where it occurs, it is intimately connected to the properties of the system at a microscopic, atomic level. Superfluidity is nevertheless associated with some spectacular large-scale effects, most notably in liquid Helium II, where under the right circumstances the fluid can for example flow up the walls and out from a confining vessel. Superfluidity is observable in a variety of physical systems, and is frequently intimately associated with the phenomenon of Bose-Einstein condensation, where, for certain kinds of identical (bosonic) particles, for low enough temperatures a significant fraction of the particles collapse into the same state, from then on in a sense acting as one. The 1995 observation of Bose-Einstein condensation in dilute atomic vapours, for which the 2001 Nobel prize was won by Eric Cornell, Wolfgang Ketterle, and Carl Wieman, thus provided a huge stimulus to the fundamental study of superfluid and related properties. This is in significant part because such dilute vapours are significantly simpler to describe and understand than the much denser systems of liquid Helium or the metals and ceramics in which the related phenomenon of superconductivity is observed. A much more recent, related phenomenon is that of so-called exciton and polariton condensates in semiconductors, with particular interest paid to the properties of the light emitted from such systems.This is an expanding field, with workers on the variety of superfluid and condensation phenomena coming from an equally broad range of scientific backgrounds. There is therefore substantial scope for interdisciplinary cooperation, particularly as a number of seemingly distinct theoretical methodologies, each with its own particular strengths and insights, have been developed independently to describe systems which appear to have many things in common. This applies particularly when attempting a precise description of dynamics (i.e., when the system is no longer at equilibrium), and when the temperature of the system is low, but noticeably greater than absolute zero. For any potential applications, such as in precision measurement of surface forces, time and frequency standards, and even the possible elucidation of gravitational effects beyond those described within Einstein's general theory of relativity, a thorough, predictive understanding of finite temperature in a non-equilibrium configuration will be essential, as well as being of fundamental physical interest. We have therefore chosen to hold the workshop FINESS, which will have an outstanding international roster of leading scientists in their fields in Durham, September 2009. This is a great opportunity for UK physics, notably for junior workers in the field attending the workshop.