2017/05/31 by Jérôme Dubail, Jean-Marie Stéphan, Pasquale Calabrese · 2 citations
Physics and Astronomy · #cond-mat.str-el #cond-mat.quant-gas #quant-ph
paper · pdf · doi:10.21468/scipostphys.3.3.019
published as SciPost Phys. 3, 019 (2017) · v1: 20 pages + refs, 7 figures. v2: references added. v3: minor changes
arxiv created 2017/07/12 · arxiv updated 2017/09/07
The light-cone spreading of entanglement and correlation is a fundamental and ubiquitous feature of homogeneous extended quantum systems. Here we point out that a class of inhomogenous Luttinger liquids (those with a uniform Luttinger parameter K) at low energy display the universal phenomenon of curved light cones: gapless excitations propagate along the geodesics of the metric ds2=dx2+v(x)2 dτ2, with v(x) being the calculable spatial dependent velocity induced by the inhomogeneity. We confirm our findings with explicit analytic and numerical calculations both in- and out-of-equilibrium for a Tonks-Girardeau gas in a harmonic potential and in lattice systems with artificially tuned hamiltonian density.