Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 68: Focus Session: Non-equilibrium Dynamics in Light-driven Materials: Theory Meets Experiment
O 68.3: Hauptvortrag
Mittwoch, 22. März 2017, 11:30–12:00, TRE Phy
Controlling magnetism and pairing in a periodically driven Hubbard model — •Stephen Clark1,2, Jonathan Coulthard3, Juan Jose Mendoza-Arenas4, Martin Eckstein2, Dieter Jaksch3, and Andrea Cavalleri2,3 — 1Department of Physics, University of Bath, UK — 2Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany — 3Department of Physics, University of Oxford, UK — 4Departamento de Fisica, Universidad de los Andes, Colombia
In this talk I will describe theory work illustrating striking effects of periodic driving for three different regimes: (i) high frequency ω ≫ U,t, (ii) resonant ω = nU and (iii) in-gap U ≫ ω ≫ t. Floquet theory when U ≫ t predicts renormalisation of t for (i), substantial modifications of both t and U for (ii) and a suppression of t with super-exchange J essentially unchanged for (iii). To demonstrate this physics I will outline non-equilibrium DMFT results showing how the mechanism governing the magnetic melting of an initial classical Neel state can be controlled and switched in the half-filled Hubbard model in infinite dimensions. I will also describe how attaining dominant super-exchange interactions in regime (iii) leads to the emergence of strong singlet-pairing correlations in the driven state. This is demonstrated in the one-dimensional Hubbard model below half-filling in the thermodynamic limit using time-dependent DMRG calculations. By spanning different fillings, dimensions and driving regimes these results show how periodic driving leads to compelling new pathways for controlling magnetism and potentially engineering light-induced superconductivity.