2018/06/25 by Raphaël Menu, Tommaso Roscilde
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Excitation #Lattice (music) #Physics #Quantum #Quantum many-body systems #Quantum mechanics #Quantum, superfluid, helium dynamics #Quasiparticle #Rydberg atom #Rydberg formula #Spin (aerodynamics) #cond-mat.quant-gas #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.98.205145
published as Phys. Rev. B 98, 205145 (2018) · 19 pages, 12 figures
arxiv created 2018/06/25 · openalex publication_date 2018/11/26 · arxiv updated 2018/12/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the unitary evolution following a quantum quench in quantum spin models possessing a (nearly) flat band in the linear excitation spectrum. Inspired by the perspective offered by ensembles of individually trapped Rydberg atoms, we focus on the paradigmatic trasverse-field Ising model on two-dimensional lattices featuring a flat band as a result of destructive interference effects (Lieb and kagom'e lattice), or a nearly flat band due to a strong energy mismatch among sublattices (triangular lattice). Making use of linear spin-wave theory, we show that quantum quenches, equipped with single-spin imaging, can directly reveal the spatially localized nature of the dispersionless excitations, and their slow propagation or lack of propagation altogether. Moreover, we show that Fourier analysis applied to the postquench time evolution of wave-vector-dependent quantities allows for the spectroscopic reconstruction of the flat bands. Our results pave the way for future experiments with Rydberg quantum simulators, which can extend our linear spin-wave study to the fully nonlinear regime, characterized by the appearance of dense, strongly interacting gases of dispersionless excitations.