Quantized topological transport mediated by the long-range couplings

Certain topological systems with time-varying Hamiltonian enable quantized and disorder-robust transport of excitations. Here, we introduce the modification of the celebrated Thouless pump when the on-site energies remain fixed, while the nearest and next-nearest neighbor couplings vary in time. We demonstrate quantized transport of excitations and propose an experimental implementation using an array of evanescently coupled optical waveguides.

💡 Research Summary

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The authors present a novel variant of the Thouless pump that eliminates the need for time‑dependent on‑site potentials and instead relies solely on the periodic modulation of nearest‑neighbor (NN) and next‑nearest‑neighbor (NNN) couplings. The model is a one‑dimensional Su‑Schrieffer‑Heeger (SSH)‑type lattice supplemented by two NNN hoppings connecting sites within the same sublattice. Its Bloch Hamiltonian reads

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