Fermi Surface Mapping Using A Third Generation Light Source

1996 ◽  
Vol 437 ◽  
Author(s):  
Eli Rotenberg ◽  
J. D. Denlinger ◽  
S. D. Kevan ◽  
K. W. Goodman ◽  
J. G. Tobin ◽  
...  
Keyword(s):  
Fermi Surface ◽  
Fermi Level ◽  
Light Source ◽  
Three Dimensional ◽  
Electronic States ◽  
Surface States ◽  
Surface Mapping ◽  
Uniform Sampling ◽  
Surface Brillouin Zone ◽  
Takeoff Angle

AbstractThe electronic states at the Fermi surface determine diverse properties such as magnetism, chemical bonding, and phonon-electron coupling. Using a conventional hemispherical analyzer at the ultraESCA beamline 7.0 of the Advanced Light Source, we have measured Fermi contours of the bulk and surface states of Cu(001) and Ag(001). For bulk states, we used uniform sampling in k-space by varying both the electron takeoff angle as well as the photon energy. Three-dimensional plots (in k-space) of bulk and surface states at the Fermi level can easily be achieved within one or two synchrotron shifts. Surface states, whose momentum is independent of k-perpendicular, are easily mapped if sufficiently dense angular sampling is performed. The states crossing the Fermi level at X in the surface Brillouin Zone of Cu(100) and Ag(100) are presented as examples.

NEW ELECTRONIC STATES ON CLEAN Si(110)-“16×2” SURFACES

1995 ◽  
Vol 02 (05) ◽  
pp. 573-577 ◽  
Author(s):  
A. CRICENTI ◽  
B. NESTERENKO ◽  
P. PERFETTI ◽  
G. LE LAY ◽  
C. SEBENNE
Keyword(s):  
Electronic Properties ◽  
Brillouin Zone ◽  
Photoelectron Spectroscopy ◽  
Structural Model ◽  
Electronic States ◽  
Surface States ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Surface Brillouin Zone ◽  
Differential Reflectivity

The electronic properties of a clean Si (110)-“16×2” surface have been studied by angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) and surface differential reflectivity (SDR). Four surface states have been recognized by ARUPS and their dispersions have been mapped along the main symmetry lines in the surface Brillouin zone. SDR experiments revealed transitions between filled and empty surface states at ~ 1.8, 2.4, and 2.9 eV. The results are explained on the basis of a new structural model of the Si (110)-“16×2” phase.

New Display-type Analyzer for Three-dimensional Fermi Surface Mapping and Atomic Orbital Analysis

2007 ◽  
Author(s):  
Nobuaki Takahashi ◽  
Fumihiko Matsui ◽  
Hiroyuki Matsuda ◽  
Shin Shigenai ◽  
Yoshiteru Hirama ◽  
...  
Keyword(s):  
Fermi Surface ◽  
Atomic Orbital ◽  
Three Dimensional ◽  
Display Type ◽  
Surface Mapping ◽  
Orbital Analysis

scholarly journals Anderson localization of electrons in single crystals: LixFe7Se8

2016 ◽  
Vol 2 (2) ◽  
pp. e1501283 ◽  
Author(s):  
Tianping Ying ◽  
Yueqiang Gu ◽  
Xiao Chen ◽  
Xinbo Wang ◽  
Shifeng Jin ◽  
...  
Keyword(s):  
Fermi Level ◽  
Single Crystals ◽  
Electrical Transport ◽  
Three Dimensional ◽  
Electronic States ◽  
Coulomb Repulsion ◽  
Experimental Investigations ◽  
Crystalline Materials ◽  
Lattice Disorder ◽  
Anderson Insulators

Anderson (disorder-induced) localization, proposed more than half a century ago, has inspired numerous efforts to explore the absence of wave diffusions in disordered media. However, the proposed disorder-induced metal-insulator transition (MIT), associated with the nonpropagative electron waves, has hardly been observed in three-dimensional (3D) crystalline materials, let alone single crystals. We report the observation of an MIT in centimeter-size single crystals of LixFe7Se8induced by lattice disorder. Both specific heat and infrared reflectance measurements reveal the presence of considerable electronic states in the vicinity of the Fermi level when the MIT occurs, suggesting that the transition is not due to Coulomb repulsion mechanism. The 3D variable range hopping regime evidenced by electrical transport measurements at low temperatures indicates the localized nature of the electronic states on the Fermi level. Quantitative analyses of carrier concentration, carrier mobility, and simulated density of states (DOS) fully support that LixFe7Se8is an Anderson insulator. On the basis of these results, we provide a unified DOS picture to explain all the experimental results, and a schematic diagram for finding other potential Anderson insulators. This material will thus serve as a rich playground for both theoretical and experimental investigations on MITs and disorder-induced phenomena.

FERMI SURFACE MAPPING BY PHOTOEMISSION

1997 ◽  
Vol 04 (02) ◽  
pp. 391-408 ◽  
Author(s):  
J. OSTERWALDER
Keyword(s):  
Fermi Surface ◽  
Photoelectron Spectroscopy ◽  
Surface States ◽  
Energy Bands ◽  
Surface Mapping ◽  
Fermi Surfaces ◽  
Magnetic Systems ◽  
Experimental Procedure ◽  
Energy Surfaces ◽  
Narrow Bands

Angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) data are usually measured spectrum by spectrum at various emission angles or photon energies in order to observe the dispersion of energy bands in solids and on their surfaces. In these lecture notes an alternative experimental procedure is described which yields a direct mapping of constant energy surfaces within the band structure, and specifically of the Fermi surface. This approach appears very promising, in particular when applied to magnetic systems and systems with narrow bands. Fermi surfaces of surface states are seen in direct relation to the underlying bulk Fermi surface.

scholarly journals New insight on the role of localisation in the electronic structure of the Si(111)(7 × 7) surfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. E. Dávila ◽  
J. Ávila ◽  
I. R. Colambo ◽  
D. B. Putungan ◽  
D. P. Woodruff ◽  
...  
Keyword(s):  
Fermi Surface ◽  
Photoelectron Spectroscopy ◽  
Surface States ◽  
Emission Angle ◽  
Final State ◽  
Surface Mapping ◽  
Arpes Data ◽  
Reconstructed Surface ◽  
Bulk Band

AbstractNew angle-resolved photoelectron spectroscopy (ARPES) data, recorded at several different photon energies from the Si(111)(7 × 7) surface, show that the well-known S1 and S2 surface states that lie in the bulk band gap are localised at specific (adatom and rest atom) sites on the reconstructed surface. The variations in the photoemission intensity from these states as a function of polar and azimuthal emission angle, and incident photon energy, are not consistent with Fermi surface mapping but are well-described by calculations of the multiple elastic scattering in the final state. This localisation of the most shallowly bound S1 state is consistent with the lack of significant dispersion, with no evidence of Fermi surface crossing, implying that the surface is not, as has been previously proposed, metallic in character. Our findings highlight the importance of final state scattering in interpreting ARPES data, an aspect that is routinely ignored and can lead to misleading conclusions.

scholarly journals Fermi surface tomography

2021 ◽  
Author(s):  
Sergey Borisenko ◽  
Alexander Fedorov ◽  
Kuibarov Andrii ◽  
Marco Bianchi ◽  
Volodymyr Bezguba ◽  
...  
Keyword(s):  
High Resolution ◽  
Fermi Surface ◽  
Monochromatic Light ◽  
Three Dimensional ◽  
Detailed Comparison ◽  
Time Interval ◽  
Short Time Interval ◽  
Light Sources ◽  
Surface Mapping ◽  
Fermi Surfaces

Abstract Fermi surfaces, three-dimensional (3D) abstract interfaces that define the occupied energies of electrons in a solid, are important for characterizing and predicting the thermal, electrical, magnetic, and optical properties of crystalline metals and semiconductors [1]. Angle-resolved photoemission spectroscopy (ARPES) is the only technique directly probing the Fermi surface by measuring the Fermi momenta ( kF ) from energy- and angular distribution of photoelectrons dislodged by monochromatic light [2]. Existing electron analyzers are able to determine a number of kF -vectors simultaneously, but current technical limitations prohibit a direct high-resolution 3D Fermi surface mapping. As a result, no such datasets exist, strongly limiting our knowledge about the Fermi surfaces and restricting a detailed comparison with the widely available nowadays calculated 3D Fermi surfaces. Here we show that using a simpler instrumentation, based on the Fourier electron optics combined with a retardation field of the detector, it is possible to perform 3D-mapping within a very short time interval and with very high resolution. We present the first detailed experimental 3D Fermi surface recorded in the full Brillouin zone along the kz-direction as well as other experimental results featuring multiple advantages of our technique. In combination with various light sources, including synchrotron radiation, our methodology and instrumentation offer new opportunities for high-resolution ARPES in the physical and life sciences.

Electronic States near the Fermi Level in the Antiferromagnetic and Ferromagnetic Spinels of Zn 1− x Cu x Cr 2 Se 4 ; 0.0 ≤ x ≤ 1.0

2002 ◽  
Vol 75 (4-5) ◽  
pp. 359-371
Author(s):  
M. Hidaka ◽  
N. Tokiwa ◽  
M. Yoshimura ◽  
H. Fujii ◽  
Jae-Young Choi ◽  
...  
Keyword(s):  
Fermi Level ◽  
Electronic States

scholarly journals Vortex states in an acoustic Weyl crystal with a topological lattice defect

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qiang Wang ◽  
Yong Ge ◽  
Hong-xiang Sun ◽  
Haoran Xue ◽  
Ding Jia ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Lattice Defect ◽  
Three Dimensional ◽  
Surface States ◽  
Real Space ◽  
Lattice Defects ◽  
One Dimensional ◽  
Topological Features ◽  
Topological Lattice

AbstractCrystalline materials can host topological lattice defects that are robust against local deformations, and such defects can interact in interesting ways with the topological features of the underlying band structure. We design and implement a three dimensional acoustic Weyl metamaterial hosting robust modes bound to a one-dimensional topological lattice defect. The modes are related to topological features of the bulk bands, and carry nonzero orbital angular momentum locked to the direction of propagation. They span a range of axial wavenumbers defined by the projections of two bulk Weyl points to a one-dimensional subspace, in a manner analogous to the formation of Fermi arc surface states. We use acoustic experiments to probe their dispersion relation, orbital angular momentum locked waveguiding, and ability to emit acoustic vortices into free space. These results point to new possibilities for creating and exploiting topological modes in three-dimensional structures through the interplay between band topology in momentum space and topological lattice defects in real space.

Fermi level tuning and the robustness of topological surface states against impurity doping in Sn doped Sb2Te2Se

2021 ◽  
Vol 118 (15) ◽  
pp. 154001
Author(s):  
Debarghya Mallick ◽  
Shoubhik Mandal ◽  
R. Ganesan ◽  
P. S. Anil Kumar
Keyword(s):  
Fermi Level ◽  
Surface States ◽  
Impurity Doping ◽  
Topological Surface
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