Physics1, 33 (2008) – Published November 3, 2008
If a magnet is small enough, an electric current carrying polarized spins can flip it around. Scientists are finding clever ways to control this spin-torque effect precisely, both for when it is wanted and when it is not.
Most applications based on magnetism are incompatible with domain walls, which interrupt a homogeneous magnetization. Scientists are turning this view around as they discover new ways to use an electric current to manipulate and store information in nanoscale domain walls.
Phys. Rev. Focus22, 7 (2008) – Published August 27, 2008
Slow-moving nanoparticles hitting a surface bounce away, but surprisingly, fast-moving ones stick. New simulations explain that the sticking occurs because the fast particles absorb the collision energy by transforming their atomic structure.
The response of nanostructured metal strips to an electromagnetic field may turn out to be similar to that of atomic gases. Periodic arrays of these artificial metal “molecules” could in principle form a metamaterial that slows light pulses and is easily integrated into optical circuits.
A molecule that links two metal electrodes could function like a chemically tunable miniature electronic device, provided that electrons can move easily across the molecular junction. A group in Leiden has now made highly conducting molecular junctions with benzene.
Modification of electromagnetic zero-point fluctuations by closely spaced conductors causes an interaction between them called the Casimir force. New experiments with nanostructured silicon substrates show that the geometry of the conducting surfaces has a large effect on this force.
Single photon emission is normally only observed in systems, such as atoms, that are quantum confined in all directions. Now, scientists have shown that carbon nanotubes, which are quasi-one-dimensional materials, can also act as single photon emitters.
Phys. Rev. Focus21, 21 (2008) – Published June 25, 2008
A new theory on the interactions of nanoparticles with laser light predicts some surprising effects when more than one particle is involved, such as a particle being drawn toward the source of the beam, against the flow of photons.