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arXiv · 1811.04001

Two-dimensional topological quantum walks in the momentum space of structured light

Alessio D'Errico·Filippo Cardano·Maria Maffei·Alexandre Dauphin·Raouf Barboza·Chiara Esposito·Bruno Piccirillo·Maciej Lewenstein·Pietro Massignan·Lorenzo Marrucci
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Abstract

Quantum walks are powerful tools for quantum applications and for designing topological systems. Although they are simulated in a variety of platforms, genuine two-dimensional realizations are still challenging. Here we present an innovative approach to the photonic simulation of a quantum walk in two dimensions, where walker positions are encoded in the transverse wavevector components of a single light beam. The desired dynamics is obtained by means of a sequence of liquid-crystal devices, which apply polarization-dependent transverse "kicks" to the photons in the beam. We engineer our quantum walk so that it realizes a periodically-driven Chern insulator, and we probe its topological features by detecting the anomalous displacement of the photonic wavepacket under the effect of a constant force. Our compact, versatile platform offers exciting prospects for the photonic simulation of two-dimensional quantum dynamics and topological systems.

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Alessio D'Errico, Filippo Cardano, Maria Maffei, Alexandre Dauphin, Raouf Barboza, Chiara Esposito, Bruno Piccirillo, Maciej Lewenstein, Pietro Massignan, Lorenzo Marrucci. 2020-02-06. Two-dimensional topological quantum walks in the momentum space of structured light. https://doi.org/10.1364/optica.365028

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