Abstract
The quasi-particle picture is a powerful tool to understand the entanglement spreading in many-body quantum systems after a quench. As an input, the structure of the excitations' pattern of the initial state must be provided, the common choice being pairwise-created excitations. However, several cases exile this simple assumption. In this work we investigate weakly-interacting to free quenches in one dimension. This results in a far richer excitations' pattern where multiplets with a larger number of particles are excited. We generalize the quasi-particle ansatz to such a wide class of initial states, providing a small-coupling expansion of the Rényi entropies. Our results are in perfect agreement with iTEBD numerical simulations.
Highlights
One of the most fundamental questions in physics is how collective statistical features emerge from a microscopic deterministic time evolution, both in the case where the model at hand is classical or quantum
Among the various out-of-equilibrium protocols, a prominent role is covered by the quantum quench [2]: in its simplicity, it provides a neat and clear framework to ask several fundamental questions
Albeit our generalized quasi-particle picture can be applied to any initial state in the form Eq (10), for the sake of clarity it is useful to refer to a simple model which displays such a structure
Summary
One of the most fundamental questions in physics is how collective statistical features emerge from a microscopic deterministic time evolution, both in the case where the model at hand is classical or quantum. [70] considered quenches in free lattice models whose couplings are periodically modulated in space with period T , leading to a quasi-particle picture with excitations generated in pairs of momenta (k1, k2), with k1 + k2 = 0 mod 2π/T , but with non-trivial quantum correlation among the different pairs. In both cases, the Wick theorem held on the initial states.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
