Monoatomic layers of carbon, known as
grapheme, possess numerous exceptional
properties. From the theoretical point of view,
one of the most interesting features is the
possibility to use a quasi-relativistic approach
for description of its properties. We will
shortly remind the connection of the Dirac model
with the dynamics of electronic excitations in
graphene. Using this model we will derive the
optical properties of grapheme at non-zero
temperature, and calculate the Casimir effect.
It will be shown that in high-temperature limit
the amplitude of the Casimir interaction of
graphene and an ideal metal tends to one half of
interaction between two ideal metals. At the
same time, for zero temperature the
graphene-metal interaction constitutes only 2.5%
of the interaction between two metals. Such
temperature enhancement of the effect is
attributed to arising of non-perturbative regime
in graphene.