Correlated Quantum and Classical Systems; Dense Light Elements and Their Combinations

这项拨款支持对轻元素的理论研究，包括氢和轻元素的组合，但要在高压和高温的条件下进行。该研究还包括在类似条件下的相关量子和经典系统的研究，但特别强调可能的新秩序状态。在这类系统中，一个日益突出的主题是超导性的基础和日益实用的领域，这是由最近在压缩锂中发现的超导性所推动的，压缩锂在48Gpa下的转变温度约为20K，如果得到证实，这将是所有元素中最高的。先前的研究表明，这些所谓的简单元素可以在类似的条件下采用相当复杂的结构。此外，观察到这些元素的结构表现出不可通约性。在MgB2的直接组合中，轻元素对超导场有如此巨大的影响，这无疑是值得注意的。这些理论研究将研究轻元素（如氢、锂等）在高压和高温下的电子特性。这些所谓的简单元素产生了意想不到的丰富结构，包括超导性。虽然这项研究是非常基础的，但其结果将对理解具有许多潜在应用的超导性非常有益。该项目将资助研究生

This grant supports theoretical studies of the light elements, including hydrogen and also the light elements in combination, but placed under conditions of high pressure and also of elevated temperature. The research also includes studies of correlated quantum and classical systems under similar conditions, but with particular emphasis on possible novel states of order. One topic of growing prominence in such systems is the fundamental and increasingly pragmatic area of superconductivity, impelled by the recent and quite dramatic discovery of superconductivity occurring in compressed lithium with a transition temperature of about 20K at 48Gpa, which if substantiated would be the highest of any element. Previous studies had shown that these so-called simple elements could adopt structures of considerable complexity at similar conditions. Further, these elements were observed to take up structures exhibiting incommensurabilities. And it is surely remarkable that the light elements in the straightforward combination MgB2 have such a dramatic effect on the field of superconductivity.%%%These theoretical studies will investigate the electronic properties of the light elements, e.g., hydrogen, lithium, etc., under high pressure and high temperatures. These so-called simple elements yield unexpected rich structures including superconductivity. While the research is very basic, the results will be very beneficial in understanding superconductivity which has many potential applications. The project will support graduate students.***