Radio communication is now possible on the most elementary
level: scientists at the ETH Zurich and the Max Planck Institute
for the Science of Light in Erlangen have used two molecules as
antennas and transmitted signals in the form of single photons,
i.e. light particles, from one to the other. Since a single
photon usually has very little interaction with a molecule, the
physicists had to use a few experimental tricks for the receiver
molecule to register the light signal. A radio connection
established via individual photons would be ideal for various
applications in quantum communication – in quantum cryptography
or in a quantum computer, for example. Individual particles of
light are the means of choice to transmit quantum bits. In the
future, the smallest units of quantum information could replace
the conventional bits if the computer advances into new
dimensions of computing speed with the aid of the special
properties of quantum physics. In quantum cryptography, single
photons are already being used a