Prof. Clement Delcamp Discusses Non-Invertible Symmetries in Quantum Lattice Models at Isaac Newton Institute Seminar

In a seminar hosted by the Isaac Newton Institute on November 5, 2025, Professor Clement Delcamp from Institut des Hautes Études Scientifiques presented a pedagogical introduction to non-invertible symmetries within one-dimensional quantum lattice models. The session was part of the program "Quantum field theory with boundaries, impurities, and defects."

Prof. Delcamp explained recent developments in constructing lattice models with non-invertible symmetries, focusing on how fusion categories can encode properties of topological defects. He elaborated on the framework that connects category theory to the physics of lattice models, illustrating how symmetries are represented as collections of topological defects and how symmetry operators can be visualized using string diagrams.

The talk also covered gauging operations, including twisted gauging, and their role in defining local actions and classifying gapped phases in quantum systems. Key mathematical structures discussed included fusion categories, twisted group algebras, and projective representations. Delcamp highlighted the importance of understanding the duality in symmetries after gauging, and how these theoretical tools help classify quantum phases and spontaneous symmetry breaking in lattice models.

Through this comprehensive seminar, Prof. Delcamp provided insights valuable for researchers studying quantum field theory, lattice models, and advanced symmetry concepts in mathematical physics.

Source: Isaac Newton Institute Seminar, Prof. Clement Delcamp, November 5, 2025