Mainz 2017 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 52: Quantum Gases: Fermions II
Q 52.3: Vortrag
Donnerstag, 9. März 2017, 15:00–15:15, P 204
One dimensional massless Lorentz Invariant Systems on Ring with magnetic Flux — •Manon Bischoff1, Johannes Jünemann1, Matteo Rizzi1, and Marco Polini2 — 1JGU Mainz — 2IIT Genua
The persistent current response of one dimensional (1D) electrons on a ring pierced by a magnetic flux has been longly studied in solid state setups. Little attention has been however devoted to systems with Dirac-cone dispersion at the Fermi-level, and the few available results are focused on the non-interacting case. Here we investigate the scaling of the current and its response with respect to system-size and interaction-strength in a (quasi-)1D Creutz ladder model with Hubbard interactions, as realisable in cold atomic setups. We present both analytical results based on bosonization and numerical results obtained using so-called binary tree-tensor networks. The current response behaves very similarly to the Drude weight of the 1D Hubbard model: it vanishes at exactly half-filling as soon as interactions are turned on (thus testifying a gap opening), while it stays finite and positive away from that (the system stays in the Luttinger liquid regime). This is instead in contrast with two dimensional massless Lorentz invariant systems, where the magnetic susceptibility (also the persistent current response to a piercing flux) away from half-filling is vanishing in the free case and interactions can induce a net negative response.