Silicon Templates for Single-Spin Magnetoelectronics

Franz J. Himpsel, University of Wisconsin-Madison, DMR 0705145

The ultimate limit for making electronic circuits smaller and smaller is reached when one bit of data is shrunk to a single electron, carrying a single spin and sitting on a single atom. We are still far away from this limit, but this work by Steven Erwin and Franz Himpsel provides a first glimpse:

Stepped silicon surfaces plus gold atoms (yellow) make it possible to place single electrons with atomic precision along the step edges. Every third edge atom carries an unpaired electron with a spin (red and blue atoms with spin arrows).

S.C. Erwin and F.J. Himpsel, Nature Communications, August 24, 2010. DOI: 10.1038/ncomms1056

These linear chains of spin-polarized atoms provide atomically perfect templates for the ultimate memory and logic, in which a single spin represents a bit. One potential application is a “spin shift register” recently proposed by Gerald D. Mahan at Penn State University. Another application is the storage of information in single magnetic atoms. Recently, several groups have demonstrated that it is possible to detect single spins at a surface by spin-polarized scanning tunneling microscopy.

This project connects the university with national research institutions, such as the Naval Research Lab. (this publication), the CNM at Sandia Natl. Lab. (a previous publication), the CINT at Argonne Natl. Lab. (a test of this work by spin-polarized STM which just produced first results), and the SRC in Madison (a Natl. Facility of the NSF, where the spectroscopy work was done). This exchange gives graduate students as well as future employers a good opportunity to get to know each other.

CINTSandia

CNMArgonne

UWMadison

NRL

SRC

Silicon Templates for Single-Spin Magnetoelectronics

Franz J. Himpsel, University of Wisconsin-Madison, DMR 0705145