Quantum information technologies hold the promise to revolutionize sensing, communication, and computing. Realizing this promise requires new approaches for creating "quantum-ready" materials and manufacturing processes. The research part of this project introduces a new class of materials called "van der Waals heterostructures" to the manufacturing of high-quality devices for application to quantum computation. Van der Waals heterostructures are a family of layered, two-dimensional (flat) materials that - depending on their design - may assume a wide range of properties, such as being a normal metal like copper, a superconductor like aluminum, or an insulator like aluminum oxide. The advantage of these materials is that they are crystalline and, therefore, have few (if any) defects. The atomically sharp interfaces of these heterostructures also provide a materials platform to build novel electronic devices. Defects limit the utility of today's quantum devices, and this research aims to improve quantum device performance by leveraging their crystallinity. The research includes characterization of the electrical and optical properties of van der Waals heterostructures, as well as their use to manufacture and test a range of quantum devices useful for quantum information processing. The project also contributes to the training of a new generation of "quantum engineers" who will translate this work into industrial settings. The investigators are committed to the mentoring and training of undergraduates, graduate students, and postdoctoral associates - the next generation of science and engineering leaders - as well as outreach to those already in the workforce and other members of the public.
This project addresses the characterization of van der Waals (vdW) heterostructures - a family of layered, crystalline, two-dimensional (2D) quantum materials including semi-metals, insulators, semiconductors, ferromagnets, superconductors, and topological insulators - and their application to quantum information technologies. While vdW materials have been extensively studied via DC transport, few experiments have probed their quantum properties in the microwave and optical regimes relevant for quantum technology applications. In this work, the research team investigates 2D vdW materials using coherent optical techniques spanning microwaves, terahertz, and optical frequencies, including direct excitation and the use of circuit quantum electrodynamics with superconducting resonators to mediate fast, ultra-sensitive pump-probe experiments and detection. The team aggregates complementary expertise in vdW materials, high-quality-factor superconducting resonators, high coherence superconducting qubits, and their integration with vdW heterostructures. Fabrication of these devices leverages a unique, state-of-the-art hermetic device foundry developed in-house, as well as state of-the-art superconducting resonator and qubit fabrication. Measurements are performed at millikelvin temperature in cryogen-free dilution refrigerators with microwave and optical access. The research targets transformative quantum information applications, including high-coherence qubits, small-form-factor microwave components, and the study of quantum spin models.
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.
