|Chem Home people faculty|
Ph.D., University of Pennsylvania, 1979, Physics
M.S., California Institute of Technology, 1975, Chemistry
B.S., California Institute of Technology, 1975, Chemistry
Sigma Xi Award, 1975, 1979
American Vacuum Society Fellowship (1975 - 1978)
I.B.M. Predoctoral Fellowship (1978 - 1979)
W. Nottingham Prize, American Physical Society, 1979
Victor K. LaMer Prize, Division of Colloid and Surface Chemistry, ACS, 1980
Alfred P. Sloan Foundation Fellowship, 1981
Fellow of the American Physical Society, 1995
Alexander von Humboldt Research Award for Senior US Scientists, 1997
AT&T Lecture, University of Wisconsin, Madison, 1997
William Draper Harkins Lecture, University of Chicago, 2000
Angstrom Lecture, University of Uppsala, Sweden, 2000
Distinguished Lecture, Ford Research Laboratory, 2000
Bonn Chemistry Prize, Germany, 2000
Bren Lecture, UC Irvine, 2001
Meloche Lecture, University of Wisconsin, Madison, 2001
Nortel Institute for Telecommunications Distinguished Lecture, University of Toronto, Canada, 2002
Malcolm Dole Distinguished Lecture, Northwestern University, 2002
George C. Pimentel Memorial Lecture, University of California, Berkeley, 2003
NANOSCIENCE: Single Molecule Imaging, Manipulation, Spectroscopy, and Chemistry; Nanomagnetism; Variable, Low Temperature Scanning Tunneling Microscopes in Ultrahigh Vacuum; Novel Instrumentation and Experimental Methods
Condensed Matter Physics and Chemistry
Our research focuses on nanoscale chemical and physical phenomena with an emphasis on probing the basic properties of single atoms and molecules in their nano-environment on solid surfaces. The goal is to obtain detailed descriptions of small molecules which form the basis for understanding chemical and physical processes at surfaces and properties of nanostructured condensed matter and molecular materials.
The understanding of matter and its interactions with the surrounding at the atomic and molecular level is the central theme of our research program. The ability to control chemistry at the level of individual atoms and molecules underpins the way they interact and use the available energy to affect chemical transformation. The study of magnetism down to single atoms allows the understanding of how the electron spins play a role in chemical and physical processes.
The scanning tunneling microscope (STM) is a tool which not only allows us literally to see individual atoms and molecules but also to manipulate and spectroscopically characterize them. It is an all-purpose tool and is in effect a nanoreactor carrying out reactions with atoms and molecules in the nanocavity of the tunnel junction. Since the coupling of electrons to the nuclear motions provides the driving force for chemical transformation, the STM with its tunneling electrons can be tuned to induce atomic motions and to dissociate and form chemical bonds.
Tunneling electrons can be spin polarized. The STM can be used to probe magnetism and the effect of magnetic impurity on superconductivity and other solid state phenomena associated with the electron spin.
We have demonstrated that chemical analysis with the STM is possible with inelastic electron tunneling spectroscopy (IETS) and have reached the limit of sensitivity of vibrational spectroscopy, that of a single bond. The ability to measure spatially resolved vibrational intensity with sub-Angstrom resolution in single molecules makes it possible to directly determine quantitatively a number of fundamentally important physical and chemical processes.
The STM can be used effectively to probe solid state and molecular materials at the spatial limit. Its versatility is reflected in a wide range of problems which have been successfully investigated. These include intramolecular energy transfer, energy dissipation resulting from bond breaking, chemical identification and structural determination of reactants and products involved in the making of individual chemical bonds and intermediates in multistep reactions, the coupling of electrons to nuclear motions via individual molecular orbitals (orbital-specific chemistry), electrical conductivity through single molecules (molecular electronics), classical and quantum diffusion (tunneling) of single hydrogen atoms, the spatially dependent interactions between two molecules, and the fundamental motions of molecules (rotation, vibration, translation).
PublicationsSingle Molecule Chemistry by Tunneling Electrons. Physical Review Letters 1997, 78, 4410. B.C. Stipe, M.A. Rezaei, W. Ho, S. Gao, M. Persson, and B.I. Lundqvist.
Inducing and Viewing the Rotational Motion of a Single Molecule. Science 1998, 279, 1907. B.C. Stipe, M.A. Rezaei, and W. Ho.
Single-Molecule Vibrational Spectroscopy and Microscopy. Science 1998, 280, 1732. B.C. Stipe, M.A. Rezaei, and W. Ho.
Coupling of Vibrational Excitation to the Rotational Motion of a Single Adsorbed Molecule. Physical Review Letters 1998, 81, 1263. B.C. Stipe, M.A. Rezaei, and W. Ho.
Localization of Inelastic Tunneling and the Determination of Atomic-Scale Structure with Chemical Sensitivity. Physical Review Letters 1999, 82, 1724. B.C. Stipe, M.A. Rezaei, and W. Ho.
Single Bond Formation and Characterization with a Scanning Tunneling Microscope. Science 1999, 286, 1719. H.J. Lee and W. Ho.
Direct Observation of the Quantum Tunneling of Single Hydrogen Atoms with a Scanning Tunneling Microscope. Physical Review Letters 2000, 85, 4566. L.J. Lauhon and W. Ho.
Development of One-Dimensional Band Structure in Artificial Gold Chains. Science 2002, 297, 1853. N. Nilius, T.M. Wallis, and W. Ho.
Single Molecule Chemistry. J. Chem. Phys. 2002, 117, 11033. W. Ho.
Vibrationally Resolved Fluorescence Excited with Submolecular Precision. Science 2003, 299, 542. X.H. Qiu, G.V. Nazin, and W. Ho.
Visualization and Spectroscopy of a Metal-Molecule-Metal Bridge. Science 2003, 302, 77. G.V. Nazin, X.H. Qiu, and W. Ho.
Complete Publication List
Member of the Technical Staff
Research CenterInstitute of Surface and Interface Science
University of California, Irvine
2162 Frederick Reines Hall
Irvine, CA 92697-4575
Telephone (949) 824-5234
FAX (949) 824-8125
Last updated: 11/21/2003