Romain Fleury

TL;DR: The acoustic analog of the Zeeman effect in a subwavelength meta-atom consisting of a resonant ring cavity biased by a circulating fluid is introduced, producing giant acoustic nonreciprocity in a compact device.

TL;DR: This work demonstrates a non-invasive, shadow-free, invisible sensor for airborne sound waves at audible frequencies, which fully absorbs the impinging signal, without at the same time perturbing its own measurement or creating a shadow.

TL;DR: It is shown that acoustic waves provide a fertile ground to apply the anomalous physics of Floquet topological insulators, and their relevance for a wide range of acoustic applications, including broadband acoustic isolation and topologically protected, nonreciprocal acoustic emitters.

TL;DR: The concept of topological order in classical acoustics is introduced, realizing robust topological protection and one-way edge propagation of sound in a suitably designed resonator lattice biased with angular momentum, forming the acoustic analogue of a magnetically biased graphene layer.

TL;DR: In this article, the authors review how reciprocity breaks down in materials with momentum bias, structured space-dependent and time-dependent constitutive properties, and constitutive nonlinearity, and report on recent advances in the modelling and fabrication of these materials, as well as on experiments demonstrating nonreciprocal acoustic and elastic wave propagation therein.