Scanning tunneling spectroscopy is used to study the dynamics of hot electrons trapped on a Cu(100) surface in field-emission resonances (FERs) above the vacuum level. Differential conductance maps show isotropic electron interference wave patterns around defects whenever their energy lies within a surface-projected band gap. Their Fourier analysis reveals a broad wave-vector distribution, interpreted as due to the lateral acceleration of hot electrons in the inhomogeneous tip-induced potential. A line-shape analysis of the characteristic constant-current conductance spectra permits establishing the relation between apparent width of peaks and intrinsic linewidth of FERs, as well as the identification of the different broadening mechanisms.
Role of the electric field in surface electron dynamics above the vacuum level
2007
Abstract
Scanning tunneling spectroscopy is used to study the dynamics of hot electrons trapped on a Cu(100) surface in field-emission resonances (FERs) above the vacuum level. Differential conductance maps show isotropic electron interference wave patterns around defects whenever their energy lies within a surface-projected band gap. Their Fourier analysis reveals a broad wave-vector distribution, interpreted as due to the lateral acceleration of hot electrons in the inhomogeneous tip-induced potential. A line-shape analysis of the characteristic constant-current conductance spectra permits establishing the relation between apparent width of peaks and intrinsic linewidth of FERs, as well as the identification of the different broadening mechanisms.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
