This Letter presents the design, fabrication, and experimental characterization of a directional threedimensional acoustic cloak for airborne sound. The cloak consists of 60 concentric acoustically rigid tori surrounding ...
[EN] The influence of losses in double-negative metamaterial slabs recently introduced by Graciá-Salgado et al. [Phys. Rev. B 88, 224305 (2013)] is comprehensively studied. Viscous and thermal losses are considered in the ...