Geometric and electronic structure of antimony on the GaAs(110) surface studied by scanning tunneling microscopy

Mårtensson, Per; Feenstra, R. M.

doi:10.1103/physrevb.39.7744

Cited by 240 publications

(104 citation statements)

References 26 publications

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“…Conductance spectra are measured using a lock-in amplifier with 50 mV modulation at a frequency of typically 1 kHz. The method of variable tip-sample separation was employed, 16 using a ramp of typically 0.1 nm/V and with broadening parameter of 0.5 V for computing the normalized conductance 17 (the results are only weakly dependent on these parameter values). Spectra for each of the 5×5, 6√3, and graphene-covered 6√3 surfaces were acquired with at least four different probe-tips; the tip-to-tip variation in the spectra is found to be considerably smaller than the change in the spectra between the former two surfaces compared to the latter.…”

Section: Methodsmentioning

confidence: 99%

Tunneling spectroscopy of graphene and related reconstructions on SiC(0001)

Nie

Feenstra

2009

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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The 5×5, 6√3×6√3-R30°, and graphene-covered 6√3×6√3-R30° reconstructions of the SiC(0001) surface are studied by scanning tunneling microscopy and spectroscopy. For the 5×5 structure a rich spectrum of surface states is obtained, with one state in particular found to be localized on top of structural protrusions (adatoms) observed on the surface. Similar spectra are observed on the bare 6√3×6√3-R30° reconstruction, and in both cases the spectra display nearly zero conductivity at the Fermi-level. When graphene covers the 6√3×6√3-R30° surface the conductivity at the Fermi-level shows a marked increase, and additionally the various surface state peaks seen in the spectrum shift in energy and fall in intensity. The influence of the overlying graphene on the electronic properties of the interface is discussed, as are possible models for the interface structure.

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Section: Methodsmentioning

confidence: 99%

Tunneling spectroscopy of graphene and related reconstructions on SiC(0001)

Nie

Feenstra

2009

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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“…The tip's density of states is tailored on Au(111) until a typical Shockley state spectrum is obtained. According to the standard normalization procedure [15], we plot (dI/dV )/(I/V ) to obtain the local density of states (LDOS). I/V is obtained by Gaussian convolution, which does not affect the peak positions.…”

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confidence: 99%

Atomic and electronic structure of a Rashbap–njunction at the BiTeI surface

et al. 2014

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The non-centro-symmetric semiconductor BiTeI exhibits two distinct surface terminations that support spinsplit Rashba surface states. Their ambipolarity can be exploited for creating spin-polarized p-n junctions at the boundaries between domains with different surface terminations. We use scanning tunneling microscopy (STM) and spectroscopy (STS) to locate such junctions and investigate their atomic and electronic properties. The Te-and I-terminated surfaces are identified owing to their distinct chemical reactivity and an apparent height mismatch of electronic origin. The Rashba surface states are revealed in the STS spectra by the onset of a van Hove singularity at the band edge. Eventually, an electronic depletion is found on interfacial Te atoms, consistent with the formation of a space-charge area in typical p-n junctions. In inversion-asymmetric systems, the spin-orbit interaction lifts the spin degeneracy. This effect can occur either at surfaces (the Rashba-Bychkov effect [1]) or in the bulk of non-centro-symmetric crystals (the Rashba-Dresselhaus effect [2,3]). Such Rashba systems are promising candidates for manipulating electron spin by means of electric field in the context of emerging spintronic devices [4]. Significant research efforts are currently directed toward the search of materials exhibiting a "giant" Rashba effect that would enable nanometer-scale spintronic devices operating at room temperature. To date, the largest spin splitting, measured by angle-resolved photoemission spectroscopy (ARPES), has been reported in the BiAg 2 /Ag(111) surface alloy [5] and both the surface and bulk states of non-centro-symmetric semiconductor BiTeI [6][7][8][9].In BiTeI, photoemission data show two distinct types of surface domains with different surface terminations (Te and I) and opposite surface band bendings that support p-or n-type surface states [8]. We anticipate that Rashba p-n junctions can be observed at the boundaries between such domains. This can be used for fulfilling another requirement for fabricating logic devices-ambipolarity, which is the possibility to control carriers' nature (electrons or holes). Moreover, a number of novel transport phenomena have been predicted for p-n junctions in systems with strong spin-orbit coupling [10][11][12][13] that can be further exploited in practical applications. In view of applications, the questions of current dissipation to the bulk or controlled growth of the junction by epitaxy are important, but well beyond the scope of this paper. Here, cleaved BiTeI is rather considered as a toy-system providing a quite unique opportunity to study a p-n junction in two dimensions.In this work, we employ scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) to locate and investigate p-n junctions naturally occurring at a cleaved BiTeI surface. The surface domains with Te and I terminations are identified owing to their distinct chemical reactivity, apparent height, and electronic structure. The onset of a van * cedric.tournier@epfl.ch Hov...

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“…Given the finite integration times available in the measurement (at least at room temperature), a practical method for achieving this range is to vary the tip-sample separation during the measurement, moving the tip towards the surface at the voltage approaches zero from one side and withdrawing it as the voltage increases on the other side of zero. 17 Subsequent normalization of the conductance, either to constant-separation or in the form ( ) ( )…”

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confidence: 99%

“…17 The computations needed for quantitative STS analysis can be divided into two steps: obtaining the potential from Poisson's equation and obtaining the tunnel current from a solution to Schrodinger's equation. In situations of accumulation or inversion, where selfconsistency is important, one iterates between these two steps.…”

mentioning

confidence: 99%

A prospective: Quantitative scanning tunneling spectroscopy of semiconductor surfaces

Feenstra

2009

Surface Science

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Geometric and electronic structure of antimony on the GaAs(110) surface studied by scanning tunneling microscopy

Cited by 240 publications

References 26 publications

Tunneling spectroscopy of graphene and related reconstructions on SiC(0001)

Tunneling spectroscopy of graphene and related reconstructions on SiC(0001)

Atomic and electronic structure of a Rashbap–njunction at the BiTeI surface

A prospective: Quantitative scanning tunneling spectroscopy of semiconductor surfaces

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