This image taken from
a computer simulation shows nanomagnets tilted
at various angles,
with the white regions indicating greater angles of tilt.
Researchers have
found that even a small tilt of 2 degrees will facilitate
magnetic switching.
(Image by Samuel Smith, UC Berkeley)
(August 4, 2015) UC Berkeley
researchers have discovered a new way to switch the polarization of
nanomagnets, paving the way for high-density storage to move from hard disks
onto integrated circuits.
The advance, to be reported Monday, Aug. 3, in the
Proceedings of the National Academy of Sciences, could lead to computers that
turn on in an instant, operate with far greater speed and use significantly
less power.
A research team led by Sayeef Salahuddin, an associate
professor of electrical engineering and computer sciences, has found that
tilting magnets slightly makes them easy to switch without an external magnetic
field. This opens the door to a memory system that can be packed onto a
microprocessor, a major step toward the goal of reducing energy dissipation in modern
electronics.
“To reduce the power draw and increase the speed, we want to
be able to manufacture a computer chip that includes memory so that it is close
to the computational action,” said Salahuddin. “However, the physics needed to
create long-term storage are not compatible with integrated circuits.”
Creating and switching polarity in magnets without an
external magnetic field has been a key focus in the field of spintronics.
Generating a magnetic field takes power and space, which is why magnets have
not yet been integrated onto computer chips.
Instead, there are separate systems for long-term magnetic
memory. These include a computer’s hard disk drive where data are stored, and
the various kinds of random-access memory, or RAM, on the integrated circuits
of the central processing unit, or CPU, where calculations and logic operations
are performed.