From magical portals created by Marvel superhero Dr Strange to Harry Potter and his friends entering platform 9 ¾ at King's Cross Train Station, invisible portals have always been quite fascinating and something that most of us dream of. Hence, it should come as no surprise that a team of scientists has been working on devising a similar invisible portal through running various experiments.
In a study published in the Physical Review Letters on June 4, a team of scientists including Huanyang Chen of Xiamen University, Rui-Xin Wu at Nanjing University shows how they built a similar invisible portal in reality. In their research paper titled, “Invisible Gateway by Superscattering Effect of Metamaterials,” scientists mentioned that illusion devices such as “superscatterer” and invisible gateway, have been studied theoretically under the theory of transformation optics and folded geometry transformations.
Through their study, scientists had to build the device using metamaterial which is an artificial structure whose components collectively exhibit properties that the individual components do not hold otherwise. With the right design, metamaterials can be used to bend light in unusual ways and they can become ‘superscatterers’ that look larger than they really are.
The team of scientists implemented the big metamaterial super-scatterer and experimentally demonstrated its effect at microwave frequencies by field-mapping technology. The team built the metamaterial with iron-rich ceramic rods and arranged them in parallel. These rods were then placed on one side of a 5-centimeter-wide gateway. Following this, the team shone microwave radiation at the opening, which helped scientists discover that the metamaterial stopped the waves from moving through the gateway, making it ‘invisible’ at microwave wavelengths.
Through this experiment, scientists have confirmed that superscattering originates from the excitation of surface plasmons. The experiment also demonstrated that an invisible gateway could stop electromagnetic waves when integrated with superscatterer in an air pathway with a width much larger than the cutoff width of the corresponding rectangular waveguide. The team claims that the results of this experiment provide a first direct observation of superscattering effect of double negative metamaterials and invisible gateway for electromagnetic waves.
If the technology is further studied and refined, it can become an ideal platform for upcoming designs of other illusion devices.