Engineering Topological QuantumMatter in Space and Time
Topology has emerged as a unifying principle in modern condensed matter physics and materials science, enabling quantum phases that are remarkably robust yet exquisitely sensitive to their underlying environment. While traditional approaches to topological materials discovery rely on chemistry, the rise of moiré quantum materials suggests a different strategy: engineering topology by tailoring the physical environment.
In this talk I will highlight my group’s recent efforts to control scalable topological quantum matter using the two most fundamental physical knobs – space and time. We constructed a unique testbed to manipulate and probe materials at femtosecond time scale and atomic-layer spatial scale [1]. In space, by epitaxially straining topological superconductors FeTexSe1-x to SrTiO3substrates, we suppress the competing antiferromagnetic phase near the FeTelimit and uncover a new tuning mechanism for topological superconductivity: electronic correlations [2]. In time, we show that topological electronic states carry intrinsic layer-dependent vibrational fingerprints. By “listening” to these frequencies as the states couple to coherent phonons, we develop a quantum stethoscope capable of resolving long-standing puzzles in magnetic topological insulators, including the elusive broken-symmetry energy gap [3,4].In combined space-time co-engineering, I will present our latest results, integrating photonic crystal cavities with ultrathin topological insulators to realize cavity-driven Floquet engineering [5]. This platform represents a new class of physical-environment control experiments, where the ground states of topological materials are reshaped simultaneously in space and time. Together, these examples illustrate a paradigm in which topological phenomena can be designed and manipulated by engineering the physical environment, and potentially stabilized near ambient conditions – opening pathways toward scalable quantum materials and devices.
[1] C. Yan et al. Rev. Sci. Instrum. 92, 113907 (2021)
[2] H. Lin et al. NatureComm. 17, 1188 (2026)
[3] W. Lee et al. Nature Phys. 19, 950 (2023)
[4] K. D.Nguyen et al. ScienceAdvances 10, eadn5696 (2024)
[5] Y. Bai et al. in preparation