Quantum Critical Behavior of One-Dimensional Soft Bosons in the Continuum
| Autor: | G. Bertaina, Davide Emilio Galli, Martina Teruzzi, Davide Pini, Stefano Rossotti |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
Quantum Monte Carlo FOS: Physical sciences General Physics and Astronomy 01 natural sciences 010305 fluids & plasmas Vector boson Quantum Gases (cond-mat.quant-gas) Luttinger liquid Quantum mechanics Lattice (order) 0103 physical sciences Exponential decay 010306 general physics Structure factor Condensed Matter - Quantum Gases Luttinger parameter Boson |
| Zdroj: | Physical review letters. 119(21) |
| ISSN: | 1079-7114 |
| Popis: | We consider a zero-temperature one-dimensional system of bosons interacting via the soft-shoulder potential in the continuum, typical of dressed Rydberg gases. We employ quantum Monte Carlo simulations, which allow for the exact calculation of imaginary-time correlations, and a stochastic analytic continuation method, to extract the dynamical structure factor. At finite densities, in the weakly-interacting homogeneous regime, a rotonic spectrum marks the tendency to clustering. With strong interactions, we indeed observe cluster liquid phases emerging, characterized by the spectrum of a composite harmonic chain. Luttinger theory has to be adapted by changing the reference lattice density field. In both the liquid and cluster liquid phases, we find convincing evidence of a secondary mode, which becomes gapless only at the transition. In that region, we also measure the central charge and observe its increase towards c = 3/2, as recently evaluated in a related extended Bose-Hubbard model, and we note a fast reduction of the Luttinger parameter. For 2-particle clusters, we then interpret such observations in terms of the compresence of a Luttinger liquid and a critical transverse Ising model, related to the instability of the reference lattice density field towards coalescence of sites, typical of potentials which are flat at short distances. Even in the absence of a true lattice, we are able to evaluate the spatial correlation function of a suitable pseudo-spin operator, which manifests ferromagnetic order in the cluster liquid phase, exponential decay in the liquid phase, and algebraic order at criticality. 11 pages, 13 figures. Added one reference, cleared discussion on liquid phase, results unchanged |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|