Physical Review X

In sight of fundamental thermal limits on further substantial performance improvements of modern digital computational processing units, wave-based analog computation is becoming an enticing alternative. A wave, as it propagates through a carefully tailored medium, performs the desired computational operation. Yet, the necessary designs are so intricate that experimental demonstrations will necessitate further technological advances. Here, we show that, counterintuitively, the carefully tailored medium can be replaced with a random medium, subject to an appropriate shaping of the incident wave front. Using tunable metasurface reflect-arrays, we demonstrate our concept experimentally in a chaotic microwave cavity. We conclude that off-the-shelf wireless communication infrastructure in combination with a simple reflect-array suffices to perform analog computation with Wi-Fi waves reverberating in a room.Received 8 May 2018Revised 13 August 2018DOI:https://doi.org/10.1103/PhysRevX.8.041037Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasRoom temperature RFWave chaosPhysical SystemsComplex mediaDisordered systemsHydrodynamic wavesRandom & disordered mediaTechniquesCavity resonatorsMicrowave techniquesAtomic, Molecular & OpticalGeneral PhysicsCondensed Matter, Materials & Applied Physics

Leveraging Chaos for Wave-Based Analog Computation: Demonstration with Indoor Wireless Communication Signals