Regensburg 2022 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 20: Topology: Poster Session

TT 20.6: Poster

Mittwoch, 7. September 2022, 15:00–18:00, P1

Current increase by weakening site-site interaction in SSH lattices — •Mirko Rossini, Brecht Donvil, and Joachim Ankerhold — Institute for Complex Quantum Systems and IQST, Ulm University, Germany

One of the simplest models supporting topologically protected states is the well-known Su-Schrieffer-Heeger (SSH) model. As a 1D chain with staggered NN hopping amplitudes, it can host two protected 0-energy modes when the distribution of hopping amplitudes is properly adjusted. These edge states are energetically relatively stable against ambient noise. thus providing natural protection from any excitation living on an edge of the chain.

In this poster, we show the realization of a current through such a chain, which in the topological regime could provide a naturally protected channel for the safe transport of excitations in space. The current is created by terminating the SSH chain at particle reservoirs. It has been shown that the edge-to-edge transport of particles in such a system is exponentially suppressed with respect to the length of the chain, preventing the practical use of this model for the stated purposes. Therefore we propose, after a brief introduction to the main properties of the SSH model, an extended model for the 1D lattice that, by weakening a small selection of hopping parameters along the chain, is able to increase the current through the edges while preserving some of the topological protection offered by the original SSH model.