New quantum states in perfectly stoichiometric high-quality single crystals obtained by solid-state electro-transport

通过固态电传输获得完美化学计量的高质量单晶中的新量子态

• 批准号: EP/H03241X/1
• 负责人: Andrew Huxley
• 金额: $ 149.14万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FH03241X%2F1
• 关键词: New; quantum; states; perfectly; stoichiometric

New methods for purifying and improving the crystalline quality of materials have repeatedly led to advances in scientific knowledge and technology. Examples include (i) Sir Humphry Davy's (1807) separation of metallic elements by electrolysis, a significant step towards making modern super-alloys, (ii) Jan Czochralski's (1909) method for crystal growth now used to produce pure single-crystals for the $300bn/year silicon semiconductor industry, and (iii) William G Pfann's (1951) development of zone-refining making available high purity Ge and GaAs leading to the discovery of new phenomena such as fractional quantum Hall states found in very high quality GaAs.It is widely accepted in the condensed matter physics community that many more self-organized states of electronic-matter exist than are presently known. The discovery of such states of matter would be comparable to the discovery of ferromagnetism, conventional superconductivity or quantum Hall states in preceding centuries. There is a widespread consensus that one should look for such states at low temperatures in materials driven to the point where conventional electronic states become unstable, specifically close to zero-temperature continuous phase transitions. The difficulty is that for the new states to form, unlike for ferromagnetism and conventional superconductivity, the host materials have to be extremely pure and free of structural defects. The benchmark for the level of perfection required is well quantified for non-conventional forms of superconductivity. Most materials, however, do not crystallize with the required perfection (even after annealing for extended times), owing to the freezing-in of defects resulting from small deviations from integer stoichiometry. The proposed research will develop apparatus to tune the composition of materials to ideal integer values, achieving a leap forward in purity and crystalline quality. Subsequently, the formation of new electronic states at low temperatures will be investigated. Although the formation of new states is anticipated on general theoretical grounds, the nature and electronic structure of these states is unknown. Spatially in-homogeneous or oscillating electronic structures are strong theoretical possibilities. The states found experimentally may confirm such predictions or might be as unexpected as superconductivity was when it was discovered just over 100 years ago. The better quality crystals that composition tuning will produce will also permit us to advance understanding of non-conventional superconductivity and charge density waves in metals by measuring quantum oscillations that are detectable only in crystals of extremely high quality.

提纯和提高材料结晶质量的新方法一再导致科学知识和技术的进步。例子包括（i）汉弗莱·戴维爵士（Sir Humphry Davy）（1807）通过电解分离金属元素，这是制造现代超合金的重要一步，（ii）扬·柴克拉斯基（Jan Czochralski）（1909）的晶体生长方法，现在用于生产纯单晶为3000亿美元/年的硅半导体工业，（3）William G Pfann（1951）对区域的发展-精炼使得高纯度Ge和GaAs可用，导致发现新现象，例如在非常高质量的GaAs中发现的分数量子霍尔态。物质物理学界认为，电子物质的自组织状态比目前已知的要多得多。这种物质状态的发现将与前几个世纪的铁磁性，传统超导性或量子霍尔态的发现相媲美。人们普遍认为，应该在低温下在材料中寻找这种状态，这些材料被驱动到传统电子状态变得不稳定的程度，特别是接近零温度连续相变。困难在于，与铁磁性和传统超导性不同，要形成新的状态，主体材料必须非常纯净，没有结构缺陷。对于非常规形式的超导性，所需的完美水平的基准是很好地量化的。然而，由于与整数化学计量的微小偏差导致的缺陷的冻结，大多数材料不能以所需的完美性结晶（即使在长时间退火之后）。拟议的研究将开发设备，将材料的组成调整到理想的整数值，实现纯度和结晶质量的飞跃。随后，将研究低温下新电子态的形成。虽然在一般的理论基础上可以预期新状态的形成，但这些状态的性质和电子结构是未知的。空间不均匀或振荡的电子结构是很强的理论可能性。实验上发现的状态可能证实了这样的预测，或者可能像超导性在100多年前被发现时一样出乎意料。成分调整将产生更好质量的晶体，这也将使我们能够通过测量只有在极高质量的晶体中才能检测到的量子振荡来推进对金属中非传统超导性和电荷密度波的理解。

项目成果

Composition-tuning in a solid-state electrotransport furnace with active thermal expansion compensation.

具有主动热膨胀补偿功能的固态电传输炉中的成分调整。

• DOI: 10.1063/1.4971300
• 发表时间: 2016
• 期刊: The Review of scientific instruments
• 作者: Schmehr JL

Modulated magnetism in PrPtAl

• DOI: 10.1038/nphys3238
• 发表时间: 2015-04-01
• 期刊: NATURE PHYSICS
• 影响因子: 19.6
• 作者: Abdul-Jabbar, Gino;Sokolov, Dmitry A.;Huxley, Andrew D.
• 通讯作者: Huxley, Andrew D.

A laboratory-based Laue X-ray diffraction system for enhanced imaging range and surface grain mapping.

基于实验室的 Laue X 射线衍射系统，用于增强成像范围和表面颗粒映射。

• DOI: 10.1107/s1600576715009097
• 发表时间: 2015-08-01
• 期刊: Journal of applied crystallography
• 影响因子: 6.1
• 作者: Whitley W;Stock C;Huxley AD
• 通讯作者: Huxley AD

Magnetic excitations in the ferromagnetic superconductor UGe 2 under pressure

压力下铁磁超导体 UGe 2 中的磁激发

• DOI: 10.1088/1742-6596/568/4/042016
• 发表时间: 2014
• 期刊: Conference Series
• 作者: Kepa M

Ferromagnetic superconductors

• DOI: 10.1016/j.physc.2015.02.026
• 发表时间: 2015-07-15
• 期刊: PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS
• 影响因子: 1.7
• 作者: Huxley, Andrew D.