A research team at the University of Bristol in the UK has discovered single-photon sources, which will help secure visual communications known as ‘quantum cryptography’.
The research paper has been published in Applied Physics Letters published by the American Institute of Physics.
Fluorescent ‘defect centers’ present in the diamond behave like nano-scale light sources. They are imprisoned in a transparent substance. They need not be stored at super cold cryogenic temperatures or imprisoned in electromagnetic fields to retain stability.
According to J. P. Hadden, a post doctoral student in the Centre for Quantum Photonics, department of electrical and electronic engineering & H. H. Wills Physics Laboratory at the University of Bristol, they can be used as origins of individual photons in safe quantum cryptography schemes.
Defect centers can also be utilized as building blocks for 'solid-state quantum computers’ using quantum effects to solve difficult issues. The light has to be sourced efficiently from the diamond substance. But the efficiency is reduced by reflection and refraction of light as it goes through the diamond-air interface. The team has recently designed a system that can efficiently etch the designs over the earlier defect centers accurately to about 100nanometers.