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arXiv · 2601.20951

Topological Acoustic Diode

Ashwat Jain·Wojciech J. Jankowski·M. Mehraeen·Robert-Jan Slager
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Abstract

We show that certain three-dimensional topological phases can act as acoustic diodes realizing nonlinear odd acoustoelastic effects. Beyond uncovering topologically-induced anomalous acoustic second-harmonic generation and rectification, we demonstrate how such nonlinear responses are uniquely captured by the momentum-space nonmetricity tensor in the quantum state Hilbert-space geometry. In addition to completing the classification of quantum geometric observables in the quadratic response regime, our findings reveal unexplored avenues for experimental realizations of acoustic diodes using effective $\theta$ vacua of axion insulators adaptable for topological engineering applications.

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Ashwat Jain, Wojciech J. Jankowski, M. Mehraeen, Robert-Jan Slager. 2026-01-28. Topological Acoustic Diode. https://arxiv.org/abs/2601.20951

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