New paradigm of quantum phase transitions discovered from entanglement measurements

How does matter acquire mass? It's a question of fundamental importance to physicists. Traditionally, we've understood that all matter in the universe gains mass through a process called spontaneous symmetry breaking. Yet, recent discoveries in both condensed matter and high-energy physics have unveiled a new mechanism of mass generation without any symmetry breaking, known as "symmetric mass generation" (SMG). In our current work, we set out to investigate whether SMG corresponds to a true continuous phase transition with universal behaviors. Using newly developed numerical probes of quantum entanglement, we delved into the heart of this phenomenon on interacting electrons on honeycomb lattice, which might find its relevance in quantum moire materials. What we discovered is that, the SMG transition is indeed a continuous phase transition, but it defies all traditional paradigms. This finding opens up exciting avenues for understanding the fundamentally new mechanism of the mass generation. This work is published on Phys. Rev. Lett. 132.156503 (2024).