Comments on reconstruction of Fermi surface from high-resolution Compton data

Physica Status Solidi (b)

Sormann

2013

The uniqueness of information contained in electron densities r(p) in the extended momentum space is pointed out, showing that certain electronic properties can be derived only from r(p), directly related to the electron Bloch wave functions. The influence of many-body effects on the electron-positron (e-p) momentum density and of the crystal lattice periodicity on scattering effects is discussed. On the example of Mg it is illustrated that for simple metals there is a unique opportunity to estimate, for e-p densities, electron-electron correlation effects quantitatively.1 Introduction The knowledge of the Fermi surface (FS) topology is crucial to understand the electron properties of quantum systems [1][2][3][4]. The FS can be determined experimentally with various methods. The most common quantum oscillatory techniques [5][6][7] allow estimation of only some quantities related to FS without a visualization of its shape. Other techniques such as Compton scattering [8,9], angular correlation of annihilation radiation (ACAR) [10,11], and angle-resolved photoemission spectroscopy (ARPES) [12] yield information on the shape of FS in the whole reciprocal space [13]. The most direct method of probing electronic structure is ARPES, also known as ARUPS (angleresolved ultraviolet photoemission spectroscopy) [14,15]. As for each method, it has also some limitations [16], such as, e.g., those appearing in studies of small elliptical FS hole pockets in hydrated sodium cobalt oxides. These pockets were seen in Shubnikov-de Haas oscillations [17], phonon softening [18] and Compton scattering experiments [19] but not in ARPES measurements [20].ACAR experiments probe the momentum density of electron-positron (e-p) pairs in the extended momentum (p) space [11,13]

“…For that one usually performs the Lock–Crisp–West (LCW) folding , converting ρ ( p ) from the extended p into the reduced k momentum space, where

ρ (k) = \sum_{bold-italicG} ρ false(bold-italicp = bold-italick + bold-italicG false) = \sum_{l} n_{l} (k) f_{l} (k)

Section: Electron–positron Pair Momentum Densitiesmentioning

confidence: 99%

Electron–positron momentum densities in crystalline solids

Physica Status Solidi (b)

Sormann

2013

“…However, even in the case of the electron-positron densities, in most cases the FS breaks at r(k) are sufficiently intense to reveal the FS topology [15,16]. As shown explicitly by Shiotani [17], the equivalent procedure to the LCW folding is Schülke's method [18] where r(k) is calculated from Fourier transform of CPs, so-called B(r)-function.…”

mentioning

confidence: 99%

Electronic structure of Mg studied by Compton scattering

Physica Status Solidi (b)

Samsel‐Czekała

Pylak

et al. 2010

The electronic structure of divalent hexagonal close packed Mg is investigated by means of the high-resolution Compton scattering. Two-dimensional (2D) electron momentum densities are reconstructed using their line integrals, derived from the plane integrals of three-dimensional (3D) electron momentum densities measured directly in the Compton experiment.The analysis is performed both in the extended and reduced zone schemes. The results are compared with corresponding densities calculated within Korringa-Kohn-Rostoker in the local density approximation (KKR-LDA) band structure theory and electron-positron densities measured in the angular correlation of annihilation radiation (ACAR) experiment.

“…The equivalent procedure to the LCW folding is Schülke's method [126] (as shown explicity by Shiotani [127] ) where ρ(k) is calculated from FT of CPs, so-called B(r) -function.…”

Section: From 1d-compton Profiles To 2d Densitiesmentioning

confidence: 99%

Fermiology via the electron momentum distribution (Review Article)

Low Temperature Physics

2009

Review Article in Low Temperature Physics 35, 599-609 (2009) devoted to the 90th birthday of Boris Verkin.Investigations of the Fermi surface via the electron momentum distribution reconstructed from either angular correlation of annihilation radiation (or Compton scattering) experimental spectra are presented. The basis of these experiments and mathematical methods applied in reconstructing three-dimensional densities from line (or plane) projections measured in these experiments are described. The review of papers where such techniques have been applied to study the Fermi surface of metallic materials with showing their main results is also done.