Scattering and induced false vacuum decay in the two-dimensional quantum Ising model

We study scattering in the quantum Ising model in two dimensions. In the ordered phase, the spectrum contains a ladder of bound states and intertwined scattering resonances, which enable various scattering channels. By preparing wave packets on a 24 × 24 lattice and evolving the state with tensor networks, we explore and characterize these regimes, ranging from elastic scattering in the perturbative regime, to non-perturbative processes closer to the critical point. Then, we break the spin inversion symmetry and study the stability of the metastable false vacuum state on the collision of its excitations. We find that a highly-energetic scattering process can induce a violent decay of the false vacuum, and investigate the spread of the resulting true vacuum bubble. Spin chains enable quantum simulation of scattering-related phenomena of interest for highenergy- and condensed-matter-physics, yet current approaches are limited to low dimensional cases. Here, the authors address this gap by studying magnon scattering in 2D quantum Ising models via tree tensor networks. This unveils new resonances and induced false vacuum decay dynamics.