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.
