Metasurface antenna to manipulate all fundamental characteristics of EM waves

"A universal metasurface antenna to manipulate all fundamental characteristics of electromagnetic wave" (2023) https://www.nature.com/articles/s41467-023-40717-9 :

> Abstract: Metasurfaces have promising potential to revolutionize a variety of photonic and electronic device technologies. However, metasurfaces that can simultaneously and independently control all electromagnetics (EM) waves’ properties, including amplitude, phase, frequency, polarization, and momentum, with high integrability and programmability, are challenging and have not been successfully attempted. Here, we propose and demonstrate a microwave universal metasurface antenna (UMA) capable of dynamically, simultaneously, independently, and precisely manipulating all the constitutive properties of EM waves in a software-defined manner. Our UMA further facilitates the spatial- and time-varying wave properties, leading to more complicated waveform generation, beamforming, and direct information manipulations. In particular, the UMA can directly generate the modulated waveforms carrying digital information that can fundamentally simplify the architecture of information transmitter systems. The proposed UMA with unparalleled EM wave and information manipulation capabilities will spark a surge of applications from next-generation wireless systems, cognitive sensing, and imaging to quantum optics and quantum information science.

Similar: "Photonic chip transforms lightbeam into multiple beams with different properties" (2022) https://news.ycombinator.com/item?id=36580151 :

"Universal visible emitters in nanoscale integrated photonics" (2022) https://opg.optica.org/optica/fulltext.cfm?uri=optica-10-7-8...

Though maybe also,

"Electrons turn piece of wire into laser-like light source" (2023) https://news.ycombinator.com/item?id=33490730 :

"Coherent Surface Plasmon Polariton Amplification via Free Electron Pumping" (2023) https://doi.org/10.21203/rs.3.rs-1572967/v1

This is really cool stuff. The "eavesdrop-proof" modulation scheme is particularly interesting - I'm curious as to why they didn't also frame that bit as also reducing interference, as it seems like it would allow a base station to steer more beams without "stepping on its own feet".

All (reversible adiabatic) quantum operators are unitary transformations of a Bloch sphere. (Basically a unit circle with complex amplitude i as the third coordinate.)

How many rotations are needed to form a Church-Turing-Deutsch- complete quantum platform?

Software defined lenses, holographic projection, and many other absolutely wild possibilities come into potential reach with this. It’s going to revolutionize a lot of fields.