August 13, 2009
Physicists create electromagnetic gateway
Chinese physicists may not yet be able to move between parallel universes or become invisible, but they've created the first tunable electromagnetic gateway.
Researchers at the Hong Kong University of Science and Technology and Fudan University in Shanghai said their concept of
a gateway that can block electromagnetic waves, but that allows the passage of other entities resembles
hidden portals or
invisibility cloaks mentioned in works of science fiction or fantasy, such as the Harry Potter series.
Previous attempts at an electromagnetic gateway were hindered by narrow bandwidth, only capturing a small range of visible light or other forms of electromagnetic radiation. But the scientists said their new configuration of metamaterials can be manipulated to have optimum permittivity and permeability -- able to insulate the electromagnetic field that encounters it with an appropriate magnetic reaction.
In the frequency range in which the metamaterial possesses a negative refraction index, people standing outside the gateway would see something like a mirror, said Huanyang Chen, who led the research.
Whether it can block all visible light depends on whether one can make a metamaterial that has a negative refractive index from 300 to 800 nanometers.
The research appears in the New Journal of Physics.