RII Track-4:NSF: Synthesis of Oxide Ferroelectric Rashba Semiconductors for Low Power Computing

在机器学习、人工智能和大数据需求的推动下，纳米电子预计将在本十年结束时消耗世界一次能源的很大一部分。虽然目前的半导体材料和技术面临着满足这些需求的挑战，但使用电子自旋而不是电荷的磁性材料是有希望的替代品。尽管有这样的希望，但磁性自旋信号的有效转换和操作仍然是一个挑战。NSF EPSCoR RII Track-4奖学金项目的目标是通过实验合成和表征一类新的材料，这种材料可以使用铁电极化有效地控制和操纵电子自旋，称为铁电Rashba半导体。PI和一名研究生将利用康奈尔大学平台的最先进的薄膜合成设施来加速实现、分析和发现界面材料(PARADIM)生长设施，以沉积候选材料并测量这些系统的性能。这种合作将提高我们对内在的自旋到电荷相互转化机制的基本理解，并可能在存储器和计算方面带来新的功能。该奖学金计划将在康奈尔大学和布朗大学之间建立长期合作关系，培训研究生先进的薄膜生长技术。此外，我们将创建一个双语推广计划，帮助普罗维登斯的高中生探索布朗纳米制造洁净室。CMOS半导体技术在可扩展性、能源消耗和减少延迟方面正迅速面临挑战。这些挑战正在推动一项重大努力，以开发基于CMOS的技术的替代方案，以满足未来计算技术的需求。自旋电子学利用了记忆和逻辑的自旋和电荷自由度，是一条很有希望的途径。然而，电荷和自旋信号之间的相互转换仍然是低效的，并且缺乏对内在的自旋到电荷相互转换机制的基本了解。这项研究合作的目标是开发一类新兴的铁电Rashba半导体(FERSCs)单晶外延氧化物薄膜异质结构，它利用室温下的铁电性和磁性来操纵用于低功率自旋电子计算范式的自旋-电荷相互转换(SCI)。康奈尔大学最先进的、由NSF资助的PARADIM分子束外延(MBE)和康奈尔材料研究中心(CCMR)(NSF材料研究科学和工程中心(MRSEC))将用于材料合成和表征。在这个项目中，研究人员的目标是优化候选FERSC异质结构的合成，表征它们的结构和铁性，将铁电性和Rashba分裂与自旋输运性质关联起来。最后，该项目将在合作者和私营部门及其各自的机构之间建立长期合作关系。持续的合作将通过三个主要机制建立：1)PI参与PARADIM的用户委员会；2)在一年一度的PARADIM暑期学校期间进行PI讲座；以及3)康奈尔PARADIM和布朗大学的联合研讨会系列，旨在促进未来的合作和从布朗到PARADIM的用户。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Driven by demands in machine learning, artificial intelligence, and big data, nanoelectronics are slated to consume a significant portion of the world's primary energy by the end of the decade. While current semiconductor materials and technologies face challenges meeting these demands, magnetic materials, which use the electron’s spin rather than charge, are promising alternatives. Despite this promise, efficient conversion and manipulation of magnetic spin signals remains a challenge. The goal of this NSF EPSCoR RII Track-4 fellowship project is to experimentally synthesize and characterize a new class of materials that can efficiently control and manipulate electron spins using ferroelectric polarization, called ferroelectric Rashba semiconductors. The PI and a graduate student will utilize the state-of-the-art thin film synthesis facilities at Cornell University’s Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM) growth facility to deposit candidate materials and measure the properties of these systems. This collaboration will improve our fundamental understanding of intrinsic spin-to-charge interconversion mechanisms and could lead to new functionalities in memory and computing. This fellowship program will establish a long-term collaboration between Cornell University and Brown University to train graduate students in advanced thin film growth techniques. Furthermore, we will create a bilingual outreach program enabling Providence high school students to explore the Brown nanofabrication clean room.CMOS semiconductor technologies are rapidly facing challenges in scalability, energy consumption, and reduced latency. These challenges are driving a significant effort to develop alternatives to CMOS-based technologies to meet the demands of future computing technologies. Spintronics, which exploits both spin and charge degrees of freedom for memory and logic, is one promising avenue. However, interconverting between charge and spin signals remains inefficient, and a fundamental understanding of intrinsic spin-to-charge interconversion mechanisms is lacking. The objective of this research collaboration is to develop an emergent class of single crystal, epitaxial oxide thin film heterostructures of ferroelectric Rashba semiconductors (FERSCs), which exploit both ferroelectricity and magnetism at room temperature to manipulate spin-to-charge interconversion (SCI) for low power spintronic computing paradigms. Cornell University’s state-of-the-art, NSF-funded PARADIM molecular-beam epitaxy (MBE) and the Cornell Center for Materials Research (CCMR), an NSF Materials Research Science and Engineering Center (MRSEC), will be used for materials synthesis and characterization. In this project, the researcher aims to optimize the synthesis of candidate FERSC heterostructures, characterize their structural and ferroic properties, correlate ferroelectricity and Rashba splitting to spin transport properties. Finally, the project will establish a long-term collaboration between the collaborator and the PI, as well as their respective institutions. A sustained collaboration will be instituted via three main mechanisms: 1) PI involvement in the user committee of PARADIM; 2) PI lecture during the annual PARADIM summer school; and 3) a Cornell PARADIM and Brown University joint seminar series designed to bolster future collaboration and users from Brown to PARADIM.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.