Semiconductor band switching by charging a small grain with a single electron

“…12. We equipped the STM with an in situ cleaver, which can be controlled from outside the cryostat, in order to cleave our samples in situ at 4.2 K. Since the STM is cooled down more than 85°C below the boiling point of oxygen, the vapor pressure of oxygen is extremely low (Ͻ10 Ϫ15 Torr).…”

Section: Methodsmentioning

confidence: 99%

Zn- and Cd-induced features at the GaAs(110) and InP(110) surfaces studied by low-temperature scanning tunneling microscopy

et al. 2001

Self Cite

View full text Add to dashboard Cite

We used a low-temperature scanning tunneling microscope to study Zn-and Cd-doping atoms near the ͑110͒-cleavage surfaces of GaAs and InP at 4.2 K. The filled-state images showed centro-symmetric elevations while the empty-state images showed circular depressions. We attribute these features to the influence of the Coulomb potential of the ionized doping atoms on the number of states available for tunneling. In a few empty-state images of the GaAs͑110͒ surface, the depressions were surrounded by maxima, which are probably direct observations of Friedel oscillations. For the InP͑110͒ surface, all depressions were surrounded by noncentrosymmetric maxima. Upon moving the tip Fermi level to the bottom of the conduction band, we observed that the depressions turned into elevations with a triangular shape for both the GaAs͑110͒ and the InP͑110͒ surface. This shape was independent of the depth of the dopants, and the chemical nature of the dopants ͑Zn or Cd͒ did not influence the triangular shape either. The orientation of these triangular features was the same for all observed doping atoms and was geometrically determined with respect to the host lattice. Furthermore, we determined the location of a triangular feature with respect to a doping atom. The features were only visible when tunneling to the impurity band suggesting that the features are a direct image of the acceptor state although the origin of the triangular shape is not clear at present.

show abstract

“…We find that the simple island charging model used in Ref. [21] is not adequate for describing our Co-InAs system. This is mainly due to the fact that onsite Coulomb repulsion for the island is the strongest bias dependent effect.…”

Section: Spatial Extent Of Ring-like Featuresmentioning

confidence: 97%

Low-Temperature Scanning Tunneling Microscopy of Ring-Like Surface Electronic Structures Around Co Islands on InAs(110) Surfaces

Muzychenko¹,

Schouteden²,

Savinov³

et al. 2009

j nanosci nanotechnol

View full text Add to dashboard Cite

We report on the experimental observation by scanning tunneling microscopy at low temperature of ring-like features that appear around Co metal islands deposited on a clean (110) oriented surface of cleaved p-type InAs crystals. These features are visible in spectroscopic images within a certain range of negative tunneling bias voltages due to the presence of a negative differential conductance in the current-voltage dependence. A theoretical model is introduced, which takes into account non-equilibrium effects in the small tunneling junction area. In the framework of this model the appearance of the ring-like features is explained in terms of interference effects between electrons tunneling directly and indirectly (via a Co island) between the tip and the InAs surface.

show abstract

Semiconductor band switching by charging a small grain with a single electron

Cited by 21 publications

References 8 publications

Applications of Scanning Tunneling Microscopy To Solid State Physics

Applications of Scanning Tunneling Microscopy To Solid State Physics

Zn- and Cd-induced features at the GaAs(110) and InP(110) surfaces studied by low-temperature scanning tunneling microscopy

Low-Temperature Scanning Tunneling Microscopy of Ring-Like Surface Electronic Structures Around Co Islands on InAs(110) Surfaces

Contact Info

Product

Resources

About