September 2007

Physicists pin down atomic spin for spintronics

Scientists who dream of shrinking computers to the nanoscale look to atomic spin as one possible building block for both processor and memory, yet setting the spin of an atom, let alone measuring it, has been a challenge.

Now, University of California, Berkeley, physicists have succeeded in measuring the spin of a single atom, moving one step closer to quantum computers and "spintronic" devices built from nanoscale transistors based on atomic spin.

Crommie, UC Berkeley post-doctoral fellow Yossi Yayon and graduate student Victor W. Brar succeeded by creating islands of cobalt atoms on a cold copper substrate (4.8 Kelvin, or -451 degrees Fahrenheit) and sprinkling these islands with atoms of either iron or chromium.

Employing a relatively new technique called low-temperature spin-polarized scanning tunneling spectroscopy - essentially a scanning, tunneling microscope that can probe the spin and energy-dependent electron density of a surface - they were able to determine the spin of isolated adatoms atop these cobalt nanoislands.