Biomedical subjects

J Kliewer

Publications and source records attributed to J Kliewer.

4 recordsLinked to original sources

PubMed2005

Role of elastic scattering in electron dynamics at ordered alkali overlayers on Cu(111).

Scanning tunneling spectroscopy of p(2 x 2) Cs and Na ordered overlayers on Cu(111) reveals similar line widths of quasi-two-dimensional quantum well states despite largely different binding energies. Detailed calculations show that 50% of the line widths are due to electron-phonon scattering while inelastic electron-electron scattering is negligible. The mechanism of enhanced elastic scattering due to Brillouin zone backfolding contributes the remaining width.

Journal Article↗

PubMed2001

Luminescence from metallic quantum wells in a scanning tunneling microscope.

The tunneling current of a scanning tunneling microscope is reported to cause light emission from the metallic quantum well system Na on Cu(111). Optical spectra along with tunneling spectroscopy show that one component of the emission is due to interband transitions between quantum well states of the Na layer. The other component is similar to plasmon-mediated emission observed previously from noble metals. The emission is a unique local probe of the electronic structure of this quantum well system.

Journal Article↗

PubMed2000

Controlled modification of individual adsorbate electronic structure

Modification of the electronic structure of a single Mn adsorbate placed within a geometrical array of adatoms on Ag(111) is observed using local spectroscopy with the scanning tunneling microscope. The changes result from coupling between the adsorbate level and surface electronic states of the substrate. These surface states are scattered coherently within the adatom array, mediating the presence and shape of the array to the adsorbate within. The dimension and geometry of the adatom array thus provide a degree of control over the induced changes.

Journal Article↗

PubMed2000

Dimensionality effects in the lifetime of surface states

A long-standing discrepancy between experimental and theoretical values for the lifetimes of holes in the surface-state electron bands on noble metal surfaces is resolved; previous determinations of both are found to have been in error. The ability of the scanning tunneling microscope to verify surface quality before taking spectroscopic measurements is used to remove the effects of defect scattering on experimental lifetimes, found to have been a significant contribution to prior determinations. A theoretical treatment of inelastic electron-electron scattering is developed that explicitly includes intraband transitions within the surface state band. In our model, two-dimensional decay channels dominate the electron-electron interactions that contribute to the hole decay and are screened by the electron states of the underlying three-dimensional electron system.

Journal Article↗