NSF BSF: Transport, Fluctuation, and Nonequilibrium Phase Transition in Atomically Thin Crystalline Van der Waals Superconductors

非技术描述：超导性是一种导体在低温下完全失去电阻率的现象，电流可以在没有能量耗散的情况下流动。从基础和应用的角度来看，对超导性的理解一直是近几十年来最具挑战性的物理问题之一。在这项工作中，极薄材料中的超导性将通过创建具有抑制无序的原子薄超导体来探索。为了解决这个具有挑战性的问题，来自哈佛大学、阿贡国家实验室和以色列巴伊兰大学的科学家将利用互补的专业知识进行实验和理论研究。这项研究工作的重点是原子薄晶体超导材料及其结构的基本理解，寻求新的物理现象的发现和探索新的量子器件概念。计划开展教育和外联项目，支持大学生和公立学校教师。通过这些研究和教育项目，研究生和本科生在高度跨学科的环境中接受教育。该国际团队将通过研究实现的合作消除研究人员之间的障碍，促进研究人员之间的互动。技术说明：本项目的研究重点是研究二维（2D）超导体的涨落和非平衡态。利用近年来发展起来的可控货车德瓦耳斯（vdW）异质结制备技术，我们将在二维超导晶体样品的基础上构造出门控可调介观器件。门/温度/磁场的霍尔效应的依赖性将被调查，以表征紧急传输现象中的玻色金属相。将探索穿过人工磁钉扎阵列的输运，实现可调谐的莫特跃迁和涡旋阻力测量，以了解超导各向异性。为了理解实验结果，将开发一个新的理论框架，用于理解非平衡相变附近的动力学性质和波动动力学。该研究项目的一部分也将与以色列的专家合作进行，他们具有互补的专门知识。二维vdW超导体中出现的新物理现象可能使量子器件应用成为可能。该项目还将为参与的博士后研究员、研究生、本科生和研究实习生提供跨学科的培训和教育。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical Description: Superconductivity is a phenomenon where a conductor loses its resistivity entirely at low temperature, and current can flow without energy dissipation. Understanding superconductivity has been one of the most challenging physics problems for past several decades both for fundamental and applicational point of view. In this work, superconductivity in extremely thin materials will be explored by creating atomically thin superconductors with suppressed disorders. To tackle this challenging problem, scientists from Harvard University, Argonne National Laboratory, and Bar Ilan University in Israel will perform the experimental and theoretical study with complementary expertise. This research effort focuses on fundamental understanding of atomically thin crystalline superconducting materials and their structures, seeking discoveries of novel physical phenomena and exploring new quantum device concepts. Work on education and outreach projects is planned, supporting undergraduates and public school teachers. Through these research and educational projects, graduate students and undergraduates are educated in a highly interdisciplinary environment. This international team will promote interaction among the researchers by removing barriers between them through the collaboration enabled by research.Technical Description: The research focus of this project is studying fluctuation and non-equilibrium states of 2-dimensional (2D) superconductivity. Employing controlled van der Waals (vdW) heterostructure fabrication techniques developed recently, gate-tunable mesoscopic devices will be constructed, based on 2D superconducting crystals samples. The gate/temperature/magnetic field dependence of the Hall effect will be investigated to characterize emergent transport phenomena in the Bose metallic phase. Transport across the artificial magnetic pining array will be explored, realizing tunable Mott transition and vortex drag measurement to understand the superconducting anisotropy. To understand experimental results, a novel theoretical framework will be developed for understanding dynamic properties and fluctuation dynamics near non-equilibrium phase transitions. A part of this research project will also be carried out in collaboration with the expert in Israel who has complementary expertise. The novel physical phenomena emerging in the 2D vdW superconductors may enable quantum device applications. This project will also allow interdisciplinary training and education for participating postdoctoral research fellows, graduate students, undergraduate students and research interns.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.