QII-TAQS: Topological Quantum Devices from Nanoscale Mechanical Control of Materials

在过去的50年里，计算能力的进步主要依赖于缩小晶体管的尺寸，晶体管是构成计算机的集成电路的基本组成部分。随着小晶体管的物理极限已经达到，进一步的进展取决于对新概念的探索。其中一个概念是量子计算，其中单个量子比特（量子位）的量子状态被操纵以实现计算性能的指数级加速。量子计算面临的一个关键挑战在于量子比特的稳定性和可操作性，量子比特高度敏感，容易受到环境的干扰。该项目探讨了拓扑量子比特的创建和操作，拓扑量子比特通过其拓扑性质免受外部扰动。该项目通过在类似晶体管的器件几何结构中对二维材料施加应力源来控制材料的超导性和拓扑性质。由于该器件的几何形状与传统晶体管相似，因此有可能为新一代量子集成电路创造一种新的基本组成元件，这种元件可以用机械原理进行控制。该项目还旨在通过大学预科、本科和研究生阶段的教育课程开发，确保量子教育社会和劳动力的增长。研究人员计划开展一项关于量子科学与工程的高中暑期课程，并在大学层面引入新的课程和认证项目。量子计算设备中的退相干一直是一个长期存在的问题。一个潜在的解决方案是使用拓扑保护的马约拉纳束缚态，这些束缚态可以融合和编织在一起来执行量子操作。本项目探索通过量子材料的机械控制来产生、检测和操纵这种拓扑保护量子态的基础。本研究的主要目标是通过控制单层材料的超导性和拓扑性质来探索和操纵马约拉纳束缚态的应变工程材料。器件级应力源用于创建全固态器件，其中二维过渡金属二碲化物合金的性能可以通过三端晶体管几何形状的应变来操纵。这样，为利用应变作为一种新型的能带拓扑和超导性控制旋钮奠定了基础。该项目采用应变工程概念，包括使用薄膜应力封盖层的静态应力源和压电氧化物的动态应力源。过渡金属二碲化物合金已经在实验和理论上证明包含大量应变可调量子相。利用这些相进行纳米应变工程，可以对超导和其他量子器件进行纳米化和控制，从而探索马约拉纳束缚态物理。这些二维材料和器件的力学特性的理论多尺度建模和仿真将反馈给实验团队，以实现应变控制量子材料的全部潜力。该项目由量子飞跃大创意计划和工程理事会的电气、通信和网络系统部门共同资助。该奖项反映了美国国家科学基金会的法定使命，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。

Advancements in computational power over the past fifty years have mostly relied on shrinking the size of the transistor, the fundamental constituent element of the integrated circuits that make up computers. As physical limits of how small transistors can be are reached, further progress depends on exploring new concepts. One of these concepts is quantum computing, in which the quantum state of individual quantum bits (qubits) is manipulated to achieve exponential speedup of computational performance. A critical challenge to quantum computing lies in the stability and manipulation of qubits, which are highly sensitive and easily perturbed by the environment. This project explores the creation and manipulation of topological qubits, which are protected against external perturbation by their topological nature. The project controls the superconducting and topological nature of materials by applying stressors to two-dimensional materials in a device geometry similar to a transistor. Since the device geometry mirrors the conventional transistor, the potential exists to create a new fundamental constituent element for an entirely new generation of quantum integrated circuits that can be controlled using mechanical principles. The project also seeks to ensure the growth of a quantum educated society and workforce through educational course development at the pre-collegiate, undergraduate, and graduate levels. The investigators plan to conduct a high-school summer program on quantum science and engineering, as well as to introduce new courses and certification programs at the university level. Decoherence in quantum computing devices has been a long-term problem. A potential solution is the use of topologically protected Majorana bound states that may be fused and braided together to perform quantum operations. This project explores the foundations of generating, detecting, and manipulating such topologically protected quantum states through the mechanical control of quantum materials. The primary goal of this research is to strain-engineer materials for the exploration and manipulation of Majorana bound states, by controlling the superconducting and topological nature of monolayer materials. Device-scale stressors are used to create a fully solid-state device where the properties of two-dimensional transition metal ditelluride alloys may be manipulated with strain in a three-terminal transistor geometry. In doing so, the basis is set for using strain as a new type of control knob for band topology and superconductivity. The project applies strain-engineering concepts, including using static stressors from thin film stress capping layers, and dynamic stressors from piezoelectric oxides. Transition metal ditelluride alloys have been shown experimentally and theoretically to contain a vast library of strain tunable quantum phases. Through nanoscale strain engineering with these phases, superconducting and other quantum devices can be nanopatterned and controlled to explore Majorana bound state physics. Theoretical multiscale modeling and simulation of the mechanical properties of these 2D materials and devices will feed back to the experimental team to achieve the full potential of strain-controlling quantum materials.This project is jointly funded by the Quantum Leap Big Idea Program and the Division of Electrical, Communication, and Cyber Systems in the Engineering Directorate.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.