Researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the University of California, Berkeley have discovered a method to monitor quantum routes showing how light diffuses in graphene. Monitored diffusion helps scientists analyze grapheme.
The team led by Feng Wang of Berkeley Lab's Materials Sciences Division observed quantum disruption in Raman diffusion, an ‘inelastic’ light diffusion. This diffusion causes either energy loss or gain. It takes place in graphene and other crystals when an inward photon stimulates an electron, creating a phonon with an energy-efficient photon. Phonons are vibrations of crystal lattice. They are called particles by quantum mechanics. Quantum particles can disturb each other. Light discharge can be monitored by monitoring the route of disturbance.
According to quantum mechanics, electrons in a material's electronic state are s called the Fermi level. All states below it are full and those above it are vacant. The states can be minimized by doping to lower the Fermi energy removing the states above it and the excitation routes. The Fermi energy of undoped grapheme is situated where its bands, looking like an upside down cone, meet the empty bands. The energy can be transported by a strong electric field.
The research paper will be published in a forthcoming issue of Nature. It is also available in the Advance Online Publication.