Shuolong Yang, assistant professor at the University of Chicago, has leveraged the capabilities of the NSF-funded 2D Crystal Consortium–Materials Innovation Platform (2DCC-MIP) to probe the layer-by-layer electronic structure of complex magnetic topological insulators. Yang’s collaboration with the 2DCC began during a 2019 visit, when he learned how the national user facility supports new faculty through access to high-quality single-crystal chalcogenide materials. His early 2DCC-enabled work rapidly produced multiple high-impact publications and contributed to his NSF CAREER, DOE Early Career, and NASA Early Career Faculty awards. In his group’s recent project, supported by 2DCC-grown manganese bismuth telluride (MBT) superlattice crystals,
Yang’s team developed a new spectroscopy technique that uses femtosecond laser excitation and time-resolved photoemission to “listen” to distinct phonon frequencies originating from specific atomic layers. By mapping these frequency signatures, the group uncovered a surprising result: the topological surface state in MBT–BT superlattices is relocated to a buried layer, explaining the long-standing puzzle of why static ARPES measurements observe a nearly gapless Dirac point despite magnetic order. This “quantum stethoscope” approach opens a powerful route to resolving layer-specific electronic states in 2D chalcogenide heterostructures. Yang’s group plans to continue collaborating with the 2DCC to explore new material systems ideally suited for this technique, reinforcing the facility’s mission of enabling transformative discoveries in 2D quantum materials.