“Modulated SPT in 1D: Classification, Crystalline Equivalent Principle and LSM constraints” by Dr. Shang-Qiang NING on Tuesday, August 25, 2026, 4:00pm CYMP522, HKU

Topological phases of matter can be protected not only by on-site symmetries, but also by crystalline symmetries. In this talk, I will present the classification of 1D symmetry-protected topological (SPT) phases protected by both on-site and crystalline symmetries—referred to as modulated SPT phases—and show how it aligns with the crystalline equivalence principle through the MPS formalism. Furthermore, I will discuss their applications to Lieb–Schultz–Mattis (LSM) constraints and non-invertible symmetries.