Is this not something we have been waiting for for centuries? đ
"After decades of physics-based theorizing, researchers have succeeded in creating a novel optical metamaterial using conventional materials. Its enhanced electromagnetic effect may make true one-way glass a reality and solar panels more efficient. ...
In optical metamaterials, however, atoms are replaced by meta-atoms that can be structurally engineered to possess properties rarely seen in nature, enabling a design that produces unique electromagnetic responses and allows the precise manipulation of light at the nanoscale.
The ability to control and manipulate light at the nanoscale opens up many applications for metamaterials across various fields. Now, researchers ... have created a new optical metamaterial that may make true one-way glass a reality. ..."
"The new metamaterial takes advantage of the nonreciprocal magnetoelectric (NME) effect. The NME effect implies a link between specific properties of the material (its magnetization and polarization) and the different field components of light or other electromagnetic waves. The NME effect is negligible in natural materials, but scientists have been trying to enhance it using metamaterials and metasurfaces because of the technological potential this would unlock.
‘So far, the NME effect has not led to realistic industrial applications. Most of the proposed approaches would only work for microwaves and not visible light, and they also couldn’t be fabricated with available technology,’ ... The team designed an optical NME metamaterial that can be created with existing technology, using conventional materials and nanofabrication techniques.
The new material opens up applications that would otherwise need a strong external magnetic field to work – for example, creating truly one-way glass. Glass that’s currently sold as ‘one-way’ is just semi-transparent, letting light through in both directions. ..."
From the abstract:
"The nonreciprocal magnetoelectric effect, also known as the Tellegen effect, promises a number of groundbreaking phenomena connected to fundamental (e.g., electrodynamics of axion and relativistic matter) and applied physics (e.g., magnetless isolators). We propose a three-dimensional metamaterial with an isotropic and resonant Tellegen response in the visible frequency range. The metamaterial is formed by randomly oriented bi-material nanocylinders in a host medium. Each nanocylinder consists of a ferromagnet in a single-domain magnetic state and a high-permittivity dielectric operating near the magnetic Mie-type resonance. The proposed metamaterial requires no external magnetic bias and operates on the spontaneous magnetization of the nanocylinders. By leveraging the emerging magnetic Weyl semimetals, we further show how a giant bulk effective magnetoelectric effect can be achieved in a proposed metamaterial, exceeding that of natural materials by almost four orders of magnitude."
A new optical metamaterial makes true one-way glass possible (Aalto University) Researchers have discovered how to make a new optical metamaterial that would underpin a variety of new technologies.
Fig. 2: Cobalt-based optical Tellegen meta-atom and isotropic Tellegen metamaterial with its effective material parameters.
No comments:
Post a Comment