Searching for fluctuation-driven superconductivity

寻找涨落驱动的超导性

• 批准号: 2885567
• 金额: --
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2885567
• 关键词: Searching; fluctuation; driven; superconductivity

Current structure search methods have had significant success in finding new superconducting materials, such as high-pressure hydrides [1]. These calculations use density functional theory to produce stable structures, and then calculate the electron-phonon coupling to calculate the superconducting transition temperature Tc. However, it is known experimentally that there are classes of materials - such as the cuprate perovskites and iron-based superconductors - that exhibit superconductivity through alternative mechanisms, such as magnetic spin fluctuations [2], and thus cannot currently be found using the above method.The aim of this project is twofold. First, an electron-phonon coupling method should be implemented using the outputs of the CASTEP density functional theory code. The second aim is to introduce a method for searching for fluctuation-driven superconductivity into DFT calculations, using the so-called "quantum order by disorder" framework [3], which should allow superconductivity based on alternative mechanisms to be explored. [1] Pickard, C. J., Errea, I., & Eremets, M. I. (2019). Superconducting Hydrides Under Pressure. The Annual Review of Condensed Matter Physics Is Annu. Rev. Condens. Matter Phys. 2020, 11, 57-76. https://doi.org/10.1146/annurev-conmatphys [2] Liu, C., Bourges, P., Sidis, Y., Xie, T., He, G., Bourdarot, F., Danilkin, S., Ghosh, H., Ghosh, S., Ma, X., Li, S., Li, Y., & Luo, H. (2022). Preferred Spin Excitations in the Bilayer Iron-Based Superconductor CaK (Fe0.96Ni0.04)4As4 with Spin-Vortex Crystal Order. Physical Review Letters, 128(13). https://doi.org/10.1103/PhysRevLett.128.137003 [3] Walker, A. H., Pickard, C. J., & Green, A. G. (2022). Introducing fluctuation-driven order into density functional theory using the quantum order-by-disorder framework. http://arxiv.org/abs/2211.03717

当前的结构搜索方法在寻找新型超导材料（例如高压氢化物）方面取得了巨大成功[1]。这些计算利用密度泛函理论产生稳定的结构，然后计算电子声子耦合来计算超导转变温度Tc。然而，通过实验已知有一类材料 - 例如铜酸盐钙钛矿和铁基超导体 - 通过替代机制（例如磁自旋波动 [2]）表现出超导性，因此目前无法使用上述方法找到.该项目的目标是双重的。首先，应使用 CASTEP 密度泛函理论代码的输出来实现电子声子耦合方法。第二个目标是引入一种在 DFT 计算中寻找涨落驱动超导性的方法，使用所谓的“量子无序有序”框架 [3]，这应该允许探索基于替代机制的超导性。 [1] Pickard, C. J.、Errea, I. 和 Eremets, M. I. (2019)。压力下的超导氢化物。凝聚态物理年度回顾是 Annu。康登斯牧师。物质物理。 2020, 11, 57-76。 https://doi.org/10.1146/annurev-conmatphys [2] Liu, C.、Bourges, P.、Sidis, Y.、Xie, T.、He, G.、Bourdarot, F.、Danilkin, S. 、Ghosh, H.、Ghosh, S.、Ma, X.、Li, S.、Li, Y. 和 Luo, H. (2022)。具有自旋涡晶序的双层铁基超导体CaK (Fe0.96Ni0.04)4As4 中的优选自旋激发。物理评论快报，128(13)。 https://doi.org/10.1103/PhysRevLett.128.137003 [3] Walker, A. H.、Pickard, C. J. 和 Green, A. G. (2022)。使用量子无序框架将涨落驱动的有序引入密度泛函理论。 http://arxiv.org/abs/2211.03717