Left handed materials (LHM) were the hot topic at the recent Progress
on Electromagnetics Research Symposium in Boston.
In left-handed materials both the permittivity (basically the response
of the material to an external electric field) and the permeability
(response to a magnetic field) have negative values. (It's rare for
a material to have either negative permittivity or negative permeability,
much less both.)
This results in a negative index of refraction; when light falls on
a LHM sample it refracts in a direction opposite to that for conventional
materials; this "left handed" property makes an LHM a great
candidate solid state filter or antenna (see Update
LHM are "metamaterials," consisting of combinations of C-shaped
metal rings (split-ring resonators, or SRR) and tiny metal rods. Although
there is still some controversy over the theoretical interpretation
of left-handed optical effects, several labs now have successfully tested
So far the split-ring resonators have been planar (they're arranged
like parallel miniature printed circuit units slotted into a motherboard)
so the optical effects have also been two-dimensional.
But now a group at ETHZ lab in Zurich are close to getting 3D resonators
to work, which would allow an LHM to operate in all three dimensions.
According to Olivier Martin (firstname.lastname@example.org, 41-163-25722) left-handed
materials "could change some fundamental concepts in telecommunications,"
especially for making possible efficient, isotropic, ultra-small antennas.
(Gay-Balmaz and Martin,
Applied Physics Letters, 29 July 2002)