A quantum field theory of melting and lattice dynamics

Toyoyuki Kitamura, Hiroomi Umezawa

E. V. Tsiper, Alexei L. Efros

Toyoyuki Kitamura

Federico Rottoli, Stefano Scopa, Pasquale Calabrese

Abstract We study the unitary time evolution of the entanglement Hamiltonian of a free Fermi lattice gas in one dimension initially prepared in a domain wall configuration. To this aim, we exploit the recent development of quantum fluctuating hydrodynamics. Our findings for the entanglement Hamiltonian are based on the effective field theory description of the domain wall melting and are expected to exactly describe the Euler scaling limit of the lattice gas. However, such field theoretical results can be recovered from high-precision numerical lattice calculations only when summing appropriately over all the hoppings up to distant sites.

Luka Pavešič, Daniel Jaschke, Simone Montangero

We investigate the dynamics of the quantum Ising model on two-dimensional square lattices up to 16 $\ifmmode\times\else\texttimes\fi{}$ 16 spins. In the ordered phase, the model exhibits dynamically constrained dynamics, leading to confinement of elementary excitations and slow thermalization. After demonstrating the signatures of confinement, we probe the dynamics of interfaces in the constrained regime through sudden quenches of product states with domains of opposite magnetization. We find that the nature of excitations can be captured by perturbation theory throughout the confining regime and identify the crossover to the deconfining regime. We systematically explore the effect of the transverse field on the modes propagating along flat interfaces and investigate the crossover from resonant to diffusive melting of a square of flipped spins embedded in a larger lattice.

Toyoyuki Kitamura