Researchers from the University of Cincinnati has developed a novel
way to control the spin of electrons using pure electric means. Before the researchers made their
breakthrough, the only way to control the spin of electrons was by
using local ferromagnets in device architectures. The scientists say
that this technique results in design complexities when the demands
for electronics require smaller and smaller transistors.
The team used a device called
a quantum point contact. Philippe
Debray, research professor in the Department of Physics in the
McMicken College of Arts & Sciences said "We
used a quantum point contact — a short quantum wire — made from
the semiconductor indium arsenide to generate strongly spin-polarized
current by tuning the potential confinement of the wire by bias
voltages of the gates that create it."
He continued
saying, "The key condition for the success of the experiment is
that the potential confinement of the wire must be asymmetric — the
transverse opposite edges of the quantum point contact must be
asymmetrical. This was achieved by tuning the gate voltages. This
asymmetry allows the electrons — thanks to relativistic effects —
to interact with their surroundings via spin-orbit coupling and be
polarized. The coupling triggers the spin polarization and the
Coulomb electron–electron interaction enhances it."
The
team says that the next step in their research is to achieve the same
results at higher temperatures using a different material like
gallium arsenide.
Via DailyTech
