2020/05/27 by Jacopo Settino, J. Settino, N. Lo Gullo +4
Physics and Astronomy · #Boson #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Lattice (music) #Physics #Quantum mechanics #Quantum, superfluid, helium dynamics #Singularity #Spectral function #Spectral properties #Statistical physics #Strong Light-Matter Interactions #cond-mat.quant-gas #cond-mat.str-el #quant-ph
paper · pdf · doi:10.1103/physrevlett.126.065301
published as Phys. Rev. Lett. 126, 065301 (2021) · 10 pages, 3 figures
arxiv created 2020/05/27 · openalex publication_date 2021/02/09 · arxiv updated 2021/02/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The single-particle spectral function of a strongly correlated system is an essential ingredient to describe its dynamics and transport properties. We develop a method to evaluate exactly the spectral function for a gas of one-dimensional bosons with infinitely strong repulsions valid for any type of external confinement. Focusing on the case of a lattice confinement, we find that the spectral function displays three main singularity lines. One of them is due uniquely to lattice effects, while the two others correspond to the Lieb-I and Lieb-II modes occurring in a uniform fluid. Differently from the dynamical structure factor, in the spectral function the Lieb-II mode shows a divergence, thus providing a route to probe such mode in experiments with ultracold atoms.