Intercalation–Defect Synergy as a Co-Design Framework for Tunable 2D Quantum Materials
ORAL · Invited
Abstract
The interplay among dimensionality, disorder, and interfacial chemistry governs the emergence of correlated and topological phases in quantum materials. In layered semiconductors, the coupling between adjacent planes can be precisely tuned through intercalation, defined as the insertion of foreign atoms, ions, or molecules into van der Waals gaps, while defect engineering modulates local bonding configurations, carrier concentration, and lattice stability. Together, these processes establish a powerful design space for controlling magnetism, charge transfer, and optical response at the atomic scale. This talk will present a data-driven framework that integrates first-principles calculations, cluster expansion modeling, and machine learning-assisted screening to elucidate the synergistic effects of intercalation and native defects in two-dimensional and quasi-two-dimensional systems. Using representative case studies, including metallocene-intercalated chalcogenide-based hybrids, the discussion will demonstrate how controlled insertion and defect configurations influence interlayer coupling, Fermi-level alignment, and the manifestation of magnetic and topological characteristics. The developed workflow identifies energetically favorable intercalants, quantifies defect thermodynamics and entropy-driven disorder at finite temperature, and formulates design rules linking structural motifs to electronic tunability. These insights establish co-design principles that integrate intercalation chemistry with defect management to achieve stable, scalable, and tunable two-dimensional heterostructures. Ongoing efforts that connect theoretical predictions with synthesis and spectroscopy will also be highlighted, emphasizing experimentally measurable indicators such as binding energy shifts, defect-healing regimes, and charge-transfer fingerprints that substantiate the theoretical trends. The presentation will conclude by outlining how this unified framework can accelerate the discovery of robust quantum materials for spintronic, optoelectronic, and sensing technologies, thereby advancing a machine-readable and reproducible paradigm for materials design across a broad class of correlated and topological systems.
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Publication:1. Kastuar, S. M., Rzepa, C., Rangarajan, S., & Ekuma, C. E. (2024). A high-throughput and data-driven computational framework for novel quantum materials. APL Machine Learning, 2(4). 2. Iloanya, A. C., Kastuar, S. M., Jana, G., & Ekuma, C. E. (2025). Atomic-scale intercalation and defect engineering for enhanced magnetism and optoelectronic properties in atomically thin GeS. Scientific Reports, 15(1), 4546. 3. Kastuar, S. M., & Ekuma, C. E. (2024). Chemically tuned intermediate band states in atomically thin Cu x GeSe/SnS quantum material for photovoltaic applications. Science Advances, 10(15), eadl6752. 4. Lian, T., Iloanya, A. C., & Ekuma, C. E. (2025). Strain-tunable magnetism in hydrogen-functionalized WSe2 monolayer. Applied Physics Letters, 126(16). 5. Lian, T., Iloanya, A. C., Kastuar, S. M., Jana, G., & Ekuma, C. E. (2025). Defect-induced bipolar magnetism in atomically thin GeS. Journal of Applied Physics, 137(23).