Recovery of local density of states using scanning tunneling spectroscopy

2009 ◽  
Vol 79 (4) ◽  
Author(s):  
M. Passoni ◽  
F. Donati ◽  
A. Li Bassi ◽  
C. S. Casari ◽  
C. E. Bottani
Keyword(s):  
Density Of States ◽  
Local Density ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Local Density Of States

Measurement of Local Density of States by Scanning Tunneling Spectroscopy at Low Temperature

1987 ◽  
Vol 26 (S3-1) ◽  
pp. 627 ◽  
Author(s):  
Hiroshi Bando ◽  
Hiroshi Tokumoto ◽  
Wataru Mizutani ◽  
Kazuhiro Endo ◽  
Shigeru Wakiyama ◽  
...  
Keyword(s):  
Low Temperature ◽  
Density Of States ◽  
Local Density ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Local Density Of States

Electronic States and Mixing of Different Symmetry or Antiferromagnetism in Vortex Cores in dx2-y2-wave Superconductivity

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3560-3565 ◽  
Author(s):  
MASAO OGATA
Keyword(s):  
Density Of States ◽  
Vortex Core ◽  
Local Density ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Local Density Of States ◽  
Zero Energy ◽  
The Core ◽  
Gutzwiller Approximation ◽  
Energy Peak

The microscopic structure of vortices in high-Tc superconductors is studied using the two-dimensional t-J model. The spatial dependences of order parameters are determined self-consistently using the Gutzwiller approximation, in which the effect of correlation is into account. In the high-doping region, the pair potential has d x2-y2-wave nature and the local density of states in the vicinity of the core shows a zero-energy peak. However, in the low-doping region, a spatially oscillating (extended) s-wave-type order parameter is locally induced around the vortex core. As a result, the local density of states near the core shows a splitting of the zero-energy peak. This gives a possible explanation for the experimental data of scanning tunneling spectroscopy for YBCO. The possibility of the antiferromagnetic vortex core is also studied by modifying the Gutzwiller approximation. It is found that, close to the boundary to the antiferromagnetically ordered state, the antiferromagnetic correlation develops inside the vortex core, even if the bulk state is the pure d-wave state. In this case the local density of states near the core does not have a zero-energy peak but instead shows a gap-like feature, which can be observed experimentally. Finally the sign change of the charge of the vortex core as a function of the doping rate is found.

PROBING THE LOCAL DENSITY OF STATES OF DILUTE ELECTRON SYSTEMS IN DIFFERENT DIMENSIONS

2003 ◽  
Vol 10 (06) ◽  
pp. 933-962 ◽  
Author(s):  
MARKUS MORGENSTERN
Keyword(s):  
Density Of States ◽  
Local Density ◽  
Electron System ◽  
Scanning Tunneling Spectroscopy ◽  
Spin Splitting ◽  
Scanning Tunneling ◽  
Electron Systems ◽  
Local Density Of States ◽  
Dimensional Electron ◽  
Dimensional Electron System

Scanning tunneling spectroscopy at T = 6 K is used to investigate the local density of states (LDOS) of electron systems belonging to the bulk conduction band of InAs. In particular, the three-dimensional electron system (3DES) of the n-doped material, an adsorbate-induced two-dimensional electron system (2DES) and the tip-induced quantum dot (0DES) are investigated at B = 0 T and B = 6 T. It is found that the 3DES at B = 0 T can be described by Bloch states weakly interacting with the potential disorder provided by ionized dopants. The 2DES at B = 0 T exhibits much stronger LDOS corrugations, stressing the tendency for weak localization in the potential disorder. In a magnetic field, 3DES and 2DES show drift states, which are expected in 2D, but are surprising in 3D, where they point to a new electron phase consisting of droplets of quasi-2D systems. The 0DES at B = 0 T reveals quantized states in accordance with Hartree calculations. At B = 6 T it exhibits Landau states with exchange enhanced spin splitting. These states are used to investigate the influence of potential disorder on the exchange enhancement, which visualizes the nonlocality of the exchange interaction.

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