Spin control of single electrons is of great interest for future
applications in electronics and spintronics. However, to observe these
phenomena at room temperature it is necessary to confine the electrons
to conductive islands with reduced size, almost atomic. Although
this type of confinement is feasible today, the technological difficulty
is to control independently the different conductive islands separated
by a few nanometers. A goal almost prohibitive.
Recently a group of researchers from the NEST laboratory, Institute of
Nanoscience CNR (CnrNano) and Scuola Normale Superiore (SNS),
coordinated by Stefano Roddaro, has shown that it is possible to control
the status of multiple nano-islands without the use of a complex
fabrication of individual nano-electrodes aligned to each island. The authors present
an innovative method that circumvents some of the key technological
difficulties, and which opens a new avenue for the realization of
devices of this type operating at room temperature. An unexpected result
and somewhat counterintuitive. "We used a technique based on the Stark effect" says
Stefano Roddaro, "which allows to influence the quantum states of electrons in different
conductive islands in a different way while
subjecting them to exactly the same external perturbation. This approach
allowed us to observe the phenomenon known as "spin blockade" at 15
degrees Kelvin, so high as never before, and opens the way to push it up all the way to
room temperature". This research was published in
Nature Nanotechnology 9. 949 (2014).
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