Low-dimensional organic and inorganic superconductors

关于减少相互作用电子系统的空间维度的影响，有一个普遍的共识：物质的量子力学性质被放大，集体状态的范围被扩大。这是电子之间相互作用的结果，这些物质的基本成分在降低的维度中可以以高度组织和集体的方式表现。这在几类材料中得到了最好的例证，特别是所谓的非常规超导体，如有机导体，高温铜酸盐，磷属元素化物等。之所以这样称呼它们，是因为除了像汞、铝等简单金属那样在足够低的温度下无电阻地携带电之外，超导性还被发现出现在其他物质状态的附近，在这些状态中，电子根据它们的磁矩或电荷集体有序，从而导致例如磁性或电荷调制结构。本五年计划致力于低维有机和无机超导体的理论描述。在这些弱耦合链系统中，通过调整外部压力或化学成分等参数，关联超导性可以从与反铁磁性，电荷密度波甚至纯一维Luttinger量子液体等其他物质状态的竞争中产生。这种相的模式，在许多方面是更广泛的非传统超导体的共同特征，基本上是由量子力学定律支配的，它的理解是， 是凝聚态物理学的一个重大挑战* 通过进一步扩展重整化群工具，我们在过去几年中积累了丰富的经验，该项目的一大类目标福尔斯方法论层面。这种方法特别适用于这些低维关联超导体，其特点是不太强的相互作用。 我们认为，在追求这一计划，我们可以坚定地建立，该方法可以给我们的相关低维超导体，具有预测能力的理论的主要成分。所有的方法论发展都集中在对实验结果的解释上。*** **

There is a consensus generalis about the impact of reducing the spatial dimension in systems of interacting electrons: quantum mechanical nature of matter is magnified and range of collective states expanded. This is a consequence of interactions between electrons, these elementary constituents of matter, which in reduced dimensions can behave in a highly organized and collective way. This is best exemplified in several classes of materials, in particular the so-called unconventional superconductors like the organic conductors, high-temperature cuprates, pnictides, … . They are thus called, because besides carrying electricity without resistance like in simple metals such as mercury, aluminium, … at sufficiently low temperature, superconductivity is found to emerge in the close proximity of other states of matter where electrons order collectively from their magnetic moments or their electric charges, leading for instance to magnetism or charge modulated structures.******The present five-year project is devoted to the theoretical description of the broad class of low dimensional organic and inorganic superconductors. In these weakly coupled chains systems, by tuning parameters such as external pressure or chemical constituents, correlated superconductivity can emerge from the competition with other states of matter like anti ferromagnetism, charge-density-wave or even a purely one-dimensional - Luttinger - quantum liquid. Such a pattern of phases, which in many aspects is a common feature of broader classes of unconventional superconductors, is essentially governed by law of quantum mechanics; its understanding represents a major challenge in condensed matter physics. *** One broad class of objectives of the project falls within the level of methodology, by further expanding renormalization group tools for which we have developed extensive experience in the last few years. This method is particularly suited for these low-dimensional correlated superconductors that are characterized by not too strong interactions. We think that in pursuing this program, we can firmly establish that the method can give us the main ingredients for a theory of correlated low dimensional superconductors that has predictive power. All the methodological developments serve to focus on the explanation of experimental results. *** **