Studying Pairing Symmetries and Quasiparticle Dynamics in 2D Superconductors Using Superconducting Quantum Circuits

Van der Waals (2D) materials are a family of two-dimensional crystals with diverse physical properties. These ultra-clean materials can be assembled in any desired order to create devices that exhibit various functionalities. Among them, 2D superconductor systems possess significant potential to enhance our understanding of superconductivity at a fundamental level and to develop new types of superconducting quantum devices for quantum technologies. This project aims to study the fundamental characteristics of Van der Waals (2D) superconductors relevant to quantum information science and technology. To explore Van der Waals materials the team will build hybrid superconducting circuits incorporating these 2D superconductors and leverage our team's expertise in circuit quantum electrodynamics (cQED), quantum transport, and time-domain operation of quantum systems to enable this research. The team will explore the following directions: 1.) Kinetic inductance and pairing symmetries in moiré superconductors; 2.) Quasiparticle dynamics in 2D superconductors; 3.) Quasiparticle blocking using gap-tunable 2D superconductors; 4.) Microwave spectroscopy of Andreev levels and quasiparticle trapping characterization in graphene Josephson junctions. The proposed projects are strategically located at the intersection of condensed matter physics, 2D materials, and quantum information sciences. The results from the proposed works are expected to advance our knowledge of:; 1.) Superconductivity in interacting, highly-correlated systems, potentially leading to a better understanding of high-TC superconductors, such as the cuprates; 2.) Superconductivity in low-dimensional systems; 3.) Quasiparticle population and dynamics in crystalline 2D superconductors; 4.) Decoherence mechanisms and mitigation of quasiparticle poisoning of superconducting qubits; 5.) Interplay between mesoscopic superconductivity, Andreev physics, and coherence of superconducting qubits. 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.