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Local density of states

About: Local density of states is a(n) research topic. Over the lifetime, 3379 publication(s) have been published within this topic receiving 76278 citation(s). The topic is also known as: LDOS.

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Journal ArticleDOI: 10.1103/PHYSREVB.31.805
Jerry Tersoff1, D. R. Hamann1Institutions (1)
15 Jan 1985-Physical Review B
Abstract: The recent development of the “scanning tunneling microscope” (STM) by Binnig et al. [8.1–5] has made possible the direct real-space imaging of surface topography. In this technique, a metal tip is scanned along the surface while ad justing its height to maintain constant vacuum tunneling current. The result is essentially a contour map of the surface. This contribution reviews the the ory [8.6–8] of STM, with illustrative examples. Because the microscopic structure of the tip is unknown, the tip wave functions are modeled as s-wave functions in the present approach [8.6, 7]. This approximation works best for small effective tip size. The tunneling current is found to be proportional to the surface local density of states (at the Fermi level), evaluated at the position of the tip. The effective resolution is roughly [2A(R+d)]1/2, where R is the effective tip radius and d is the gap distance. When applied to the 2x1 and 3x1 reconstructions of the Au(l10) surface, the theory gives excellent agreement with experiment [8.4] if a 9 A tip radius is assumed. For dealing with more complex or aperiodic surfaces, a crude but convenient calculational technique based on atom charge superposition is introduced; it reproduces the Au(l10) results reasonably well. This method is used to test the structure-sensitivity of STM. The Au(l10) image is found to be rather insensitive to the position of atoms beyond the first atomic layer.

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2,941 Citations


Open accessJournal ArticleDOI: 10.1038/NPHYS781
Jens Martin1, Nitzan Akerman1, G. Ulbricht2, Timm Lohmann2  +4 moreInstitutions (3)
01 Feb 2008-Nature Physics
Abstract: The electronic structure of graphene causes its charge carriers to behave like relativistic particles. For a perfect graphene sheet free from impurities and disorder, the Fermi energy lies at the so-called ‘Dirac point’, where the density of electronic states vanishes. But in the inevitable presence of disorder, theory predicts that equally probable regions of electron-rich and hole-rich puddles will arise. These puddles could explain graphene’s anomalous non-zero minimal conductivity at zero average carrier density. Here, we use a scanning single-electron transistor to map the local density of states and the carrier density landscape in the vicinity of the neutrality point. Our results confirm the existence of electron–hole puddles, and rule out extrinsic substrate effects as explanations for their emergence and topology. Moreover, we find that, unlike non-relativistic particles the density of states can be quantitatively accounted for by considering non-interacting electrons and holes.

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Topics: Local density of states (60%), Density of states (57%), Graphene (52%) ...read more

1,388 Citations


Journal ArticleDOI: 10.1126/SCIENCE.262.5131.218
08 Oct 1993-Science
Abstract: A method for confining electrons to artificial structures at the nanometer lengthscale is presented. Surface state electrons on a copper(111) surface were confined to closed structures (corrals) defined by barriers built from iron adatoms. The barriers were assembled by individually positioning iron adatoms with the tip of a 4-kelvin scanning tunneling microscope (STM). A circular corral of radius 71.3 A was constructed in this way out of 48 iron adatoms. Tunneling spectroscopy performed inside of the corral revealed a series of discrete resonances, providing evidence for size quantization. STM images show that the corral's interior local density of states is dominated by the eigenstate density expected for an electron trapped in a round two-dimensional box.

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1,301 Citations


Book ChapterDOI: 10.1007/978-94-011-1812-5_5
Jerry Tersoff1, D. R. Hamann1Institutions (1)
01 Jan 1985-
Abstract: The recent development of the “scanning tunneling microscope” (STM) by Binnig et al. [8.1–5] has made possible the direct real-space imaging of surface topography. In this technique, a metal tip is scanned along the surface while ad justing its height to maintain constant vacuum tunneling current. The result is essentially a contour map of the surface. This contribution reviews the the ory [8.6–8] of STM, with illustrative examples. Because the microscopic structure of the tip is unknown, the tip wave functions are modeled as s-wave functions in the present approach [8.6, 7]. This approximation works best for small effective tip size. The tunneling current is found to be proportional to the surface local density of states (at the Fermi level), evaluated at the position of the tip. The effective resolution is roughly [2A(R+d)]1/2, where R is the effective tip radius and d is the gap distance. When applied to the 2x1 and 3x1 reconstructions of the Au(l10) surface, the theory gives excellent agreement with experiment [8.4] if a 9 A tip radius is assumed. For dealing with more complex or aperiodic surfaces, a crude but convenient calculational technique based on atom charge superposition is introduced; it reproduces the Au(l10) results reasonably well. This method is used to test the structure-sensitivity of STM. The Au(l10) image is found to be rather insensitive to the position of atoms beyond the first atomic layer.

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1,064 Citations


Journal ArticleDOI: 10.1038/363524A0
01 Jun 1993-Nature
Abstract: ELECTRONS occupying surface states on the close-packed surfaces of noble metals form a two-dimensional nearly free electron gas1–3. These states can be probed using the scanning tunnelling microscope (STM), providing a unique opportunity to study the local properties of electrons in low-dimensional systems4. Here we report the direct observation of standing-wave patterns in the local density of states of the Cu(lll) surface using the STM at low temperature. These spatial oscillations are quantum-mechanical interference patterns caused by scattering of the two-dimensional electron gas off step edges and point defects. Analysis of the spatial oscillations gives an independent measure of the surface state dispersion, as well as insight into the interaction between surface-state electrons and scattering sites on the surface.

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Topics: Local density of states (63%), Surface states (56%), Scattering (55%) ...read more

907 Citations


Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20222
2021112
2020108
2019108
2018111
2017114

Top Attributes

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Topic's top 5 most impactful authors

Yukio Tanaka

53 papers, 1.1K citations

C. S. Ting

24 papers, 335 citations

Masanori Ichioka

21 papers, 600 citations

Satoshi Kashiwaya

17 papers, 535 citations

Kazushige Machida

17 papers, 542 citations

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