Atomic scale characterization and fabrication
(left)Image of an elliptical quantum corral built using the autonomous atom assembler
(right) Image of the scattering pattern from a lattice defect in bilayer graphene
The goal of the atomic-scale characterization and fabrication program in the Electron Physics Group is to develop new measurement science and fabrication techniques with atomic-scale precision. Using state-of-the-art scanned probe techniques, we explore a diverse set of research areas including:
- Future electronics and spintronics
- Atom manipulation
- Spin dependence in scanned probe microscopy measurements
- Epitaxial growth
- Correlation of microstructure and magnetism
- Electronic properties of nanostructures
Our main experimental tool is the scanning tunneling microscope (STM). The STM is a highly sensitive probe of surfaces which utilizes the quantum mechanical principle of tunneling. In operation, a fine probe tip is brought to within a fraction of a nanometer from a surface to establish a tunneling current between the probe tip and the surface. The tip is rastered across the surface and the tunneling current is used in a feedback loop to servo the tip position. The measurement of the tip position is recorded as the tip-sample distance is adjusted to maintain a constant tunneling current. To first order such a raster image yields the surface topography. In addition to topographic features, the STM is inherently sensitive to surface electronic properties due to the dependence of the tunneling process on the availability of electron states. We exploit such a sensitivity to detect the surface electron density of states, and in certain cases, this allows us to selectively image different chemical species. We also use the STM to fabricate perfect nanostructures on an atom-by-atom basis. Here, an adatom is manipulated using the interactions in the tip/sample junction, and moved to a desired location under the control of the STM tip. Our experimental efforts emphasize the custom design of instrumentation with which we strive to push the frontiers of measurement in the nanometer-scaled world.
Millikelvin STM Laboratory
Nanoscale Physics Facility
Ultra-high Vacuum STM Laboratory
Future Electronics and Spintronics
- Electron Transport in Graphene
- Adatom Induced 2DEG in InAs
- Spin Dependent Structure of Mn in GaAs
- Electronically Induced Atom Motion in CoCun
Nanostructures
- Atom Dynamics in Atom Manipulation
- Autonomous Atom Assembly
- Effect of Electronic Structure on the Lengths of Atomic Chains
- Spectroscopy of Quantized States in Finite Atomic Chains
- Electronic Properties of 1-d, 2-d, and 3-d Cs Structures on GaAs(110)
- Electronic Properties of Fe Clusters on GaAs(110)
- Pattern Formation in Fe on Fe homoepitaxy
- Scaling of Island Size Distributions in Fe Growth
- Growth of Fe on Fe(001) and Correlation with RHEED
- Growth of Fe on Au(111)
- Insight into Non-Collinear Exchange Coupling of Fe/Mn/Fe from STM
- Alloying at the Cr/Fe Interface
- Influence of Cr Thickness Fluctuation in Fe/Cr/Fe
- Polarized light emission from the Metal-Metal STM junction
- Tunneling Spectroscopy of Fe and Cr(001) Surface States
Joseph A. Stroscio - NIST
Daniel T. Pierce - NIST
Robert J. Celotta - NIST
Steven R. Blankenship - NIST
Young Jae Song - University of Maryland
Stephen Balakirsky - NIST (MEL)
Francesca Tavazza - NIST (CSTL)
Anne Chaka - NIST (CSTL)
Phillip First - Georgia Institute of Technology
Gregory Rutter - Georgia Institute of Technology
Ali Yazdani - Princeton University
Anthony Richardella - Princeton University
Jason Crain
Angela Davies - University of North Carolina - Charlotte
Robert Dragoset - NIST (PL)
Aaron Fein - NIST (PL)
Phillip First - Georgia Institute of Technology
Nathan Guisinger - Argonne National Laboratory
Eric Hudson - Massachusetts Institute of Technology
Chad Sosolik - Clemson University
Lloyd Whitman - Naval Research Laboratory
J. William Gadzuk - NIST (PL)
John Cugini - NIST (retired)
Alberto Lacaze - NIST (retired)
Leonard M. Sander - University of Michigan
Michael Weinert - Brookhaven National Laboratory
Andrew Zangwill - Georgia Institute of Technology
Supported in part by the Office of Naval Research
Online: August 1995
Last Updated: February 2008
Website Comments:egpwebmaster@nist.gov