Haruki Watanabe: Spontaneous Symmetry Breaking and Low-Energy Excitations in Gapless Frustration... скачать в хорошем качестве

Haruki Watanabe: Spontaneous Symmetry Breaking and Low-Energy Excitations in Gapless Frustration...

Title: Spontaneous Symmetry Breaking and Low-Energy Excitations in Gapless Frustration Free Systems Abstract: Frustration-free Hamiltonians, such as the AKLT model and the Kitaev toric code, have helped us understand non-trivial topological phases of matters. In recent years, studies on gapless frustration-free Hamiltonians revealed that their finite-size gaps and low-energyexcitations tend to behave differently from conventional systems. As a consequence, spontaneous breaking of continuous symmetries may occur even in one dimension, contrary to the Hohenberg-Mermin-Wagner theorem. In this talk, we will review recent theoretical advances in understanding on the general properties of gapless frustration-free systems. References: HW, H. Katsura, J.-Y. Lee, arXiv:2310.16881 R. Masaoka, T. Soejima, HW, arXiv:2406.06414 R. Masaoka, T. Soejima, HW, arXiv:2406.06415