Artificial Magnetic Fields For Photons
Photons became a hot research topic due to their important role in holding data across long distances. Starting from the fact that photons are insensitive to magnetic fields which concludes to their disability to process data, a group of researchers from the ETH (Eidgenössische Technische Hochschule) in Zürich are trying to make photons controlled with electric fields by giving them some electrical charge.
Photons or Polaritons?
They are using polaritons in their approach to build this artificial magnetic field. Polaritons are hybrid particles consist of coupling a photon with an electric dipole. When photons enter a material, the electrons allow themselves to be moved by the light waves or ‘polarize’, they form polaritons – coupled light and polarization waves, or excitons. Meaning that they could convert photons into polaritons. Packing excitons with them as a luggage, we can now steer polaritons indirectly by the magnetic fields.
“The combined effect of magnetic and electric fields on polaritons then leads to a gauge potential”, says Hyang-Tag Lim, a post-doctoral researcher in Imamoğlu’s laboratory.
Researches are comparing the gauge potential to a tiltable lifting platform. For example, when trying to lift a vehicle, the potential energy will change, but the vehicle won’t move. However, once we tilt the platform, a difference in height along the platform happens and the vehicle will move. Thus, a gauge potential will result in an effective magnetic field only if it varies in space.
The researchers are now looking for ways to strengthen gauge potentials. Researchers had published this researchers in the scientific journal Nature Communications, you can have a look at the research here.
Source: ETH Zurich