论文标题
在非规范的自由度上
On non-canonical degrees of freedom
论文作者
论文摘要
非规范的自由度为表征凝结物理学中一系列重要现象提供了最有希望的途径之一。潜在的候选人包括丘比特人的伪制度，繁重的弗里米亚行为，以及确实有磁有序的系统。然而，这仍然是一个悬而未决的问题，非典型代数实际上是否可以提供合法的量子自由度。在本手稿中，我们调查了有关此主题的进度，并补充了不同的方法，以获得统一的描述。特别是，我们获得了一种新型的闭合表达，以用于非典型自由度的自我能源样物体。我们进一步重新调整了密度相关性，以获得常规自由度通常使用的RPA和GW近似的类似物。我们讨论与生成与保护法律一致的高阶近似相关的困难，该法律代表了一个杰出的问题。我们还讨论了规范和非典型的自由度之间的相互作用如何为组织相关电子行为的相图提供了有用的范式。
Non-canonical degrees of freedom provide one of the most promising routes towards characterising a range of important phenomena in condensed matter physics. Potential candidates include the pseudogap regime of the cuprates, heavy-fermion behaviour, and also indeed magnetically ordered systems. Nevertheless it remains an open question whether non-canonical algebras can in fact provide legitimate quantum degrees of freedom. In this manuscript we survey progress made on this topic, complementing distinct approaches so as to obtain a unified description. In particular we obtain a novel closed-form expression for a self-energy-like object for non-canonical degrees of freedom. We further make a resummation of density correlations to obtain analogues of the RPA and GW approximations commonly employed for canonical degrees of freedom. We discuss difficulties related to generating higher-order approximations which are consistent with conservation laws, which represents an outstanding issue. We also discuss how the interplay between canonical and non-canonical degrees of freedom offers a useful paradigm for organising the phase diagram of correlated electronic behaviour.
