Probing infinite many-body quantum systems with finite-size quantum simulators
Abstract
Experimental studies of synthetic quantum matter are necessarily restricted to approximate ground states prepared on finite-size quantum simulators. In general, this limits their reliability for strongly correlated systems, for instance, in the vicinity of a quantum phase transition (QPT). Here, we propose a protocol that makes optimal use of a given finite-size simulator by directly preparing, on its bulk region, a mixed state representing the reduced density operator of the translation-invariant infinite-sized system of interest. This protocol is based on coherent evolution with a local deformation of the system Hamiltonian. For systems of free fermions in one and two spatial dimensions, we illustrate and explain the underlying physics, which consists of quasi-particle transport towards the system's boundaries while retaining the bulk "vacuum". For the example of a non-integrable extended Su-Schrieffer-Heeger model, we demonstrate that our protocol enables a more accurate study of QPTs. In addition, we demonstrate the protocol for an interacting spinful Fermi-Hubbard model with doping for 1D chains and a small two-leg ladder, where the initial state is a random superposition of energetically low-lying states.
Cite
@article{arxiv.2108.12378,
title = {Probing infinite many-body quantum systems with finite-size quantum simulators},
author = {Viacheslav Kuzmin and Torsten V. Zache and Christian Kokail and Lorenzo Pastori and Alessio Celi and Mikhail Baranov and Peter Zoller},
journal= {arXiv preprint arXiv:2108.12378},
year = {2022}
}