Anomalous domain wall condensation in a modified Ising chain

摘要: We construct a one-dimensional local spin Hamiltonian with an intrinsically nonlocal, and therefore anomalous, global ${\mathbb{Z}}_{2}$ symmetry. The model is closely related to the quantum Ising in transverse magnetic field, contains parameter that can be tuned spontaneously break nonlocal constructed capture unconventional properties of domain walls symmetry-broken phase. Using uniform matrix product states, we obtain phase diagram results from condensing walls. find complete includes gapless separated ordered ferromagnetic by Berezinskii-Kosterlitz-Thouless transition, antiferromagnetic first-order transition.