Hannover 2016 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 53: Quantum Gases: Fermions I

Q 53.6: Talk

Thursday, March 3, 2016, 15:45–16:00, e001

Persistent currents of massless Dirac fermions with interactions — •Johannes Jünemann^1,2 and Matteo Rizzi¹ — ¹Johannes Gutenberg-Universität, 55099 Mainz, Germany — ²Graduate School Materials Science in Mainz, 55128 Mainz, Germany

The persistent current response of ring-shaped materials to a piercing magnetic flux is a traditional topic in condensed matter: the effect of impurities/disorder and/or interactions have been thoroughly studied. Little attention has been however devoted to systems with Dirac-cone dispersion relation 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 (the so-called orbital magnetic response or Drude weight) with respect to system-size and interaction-strength in a (quasi-)1D ring filled with massless Dirac fermions. We present both analytical results and numerical results obtained using so-called binary tree-tensor networks. We envisage an implementation via a Creutz ladder Hamiltonian with periodic boundary conditions, as made possible in cold-atomic setups by laser-assisted transfer processes (spin-flips, complex hopping, spin-orbit coupling) and recent progresses in shaping trapping potentials.