Introduction

Szcześniak, Paweł

doi:10.1007/978-1-4471-4896-8_1

Cited by 4 publications

(4 citation statements)

References 91 publications

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“…This PFMT method is applied in particular to calculate the quantum electronic conductance across wire nanojunctions held between onedimensional electric leads. The presented PFMT formalism provides a compact and efficient approach for the analysis of the electronic quantum transport for a wide range of wire nanojunctions [58].…”

Section: Discussionmentioning

confidence: 99%

Electronic conductance via atomic wires: a phase field matching theory approach

Szczęśniak

Khater

2012

Eur. Phys. J. B

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A model is presented for the quantum transport of electrons, across finite atomic wire nanojunctions between electric leads, at zero bias limit. In order to derive the appropriate transmission and reflection spectra, familiar in the Landauer-Büttiker formalism, we develop the algebraic phase field matching theory (PFMT). In particular, we apply our model calculations to determine the electronic conductance for freely suspended monatomic linear sodium wires (MLNaW) between leads of the same element, and for the diatomic copper-cobalt wires (DLCuCoW) between copper leads on a Cu(111) substrate. Calculations for the MLNaW system confirm the correctness and functionality of our PFMT approach. We present novel transmission spectra for this system, and show that its transport properties exhibit the conductance oscillations for the odd-and even-number wires in agreement with previously reported first-principle results. The numerical calculations for the DLCuCoW wire nanojunctions are motivated by the stability of these systems at low temperatures. Our results for the transmission spectra yield for this system, at its Fermi energy, a monotonic exponential decay of the conductance with increasing wire length of the Cu-Co pairs. This is a cumulative effect which is discussed in detail in the present work, and may prove useful for applications in nanocircuits. Furthermore, our PFMT formalism can be considered as a compact and efficient tool for the study of the electronic quantum transport for a wide range of nanomaterial wire systems. It provides a trade-off in computational efficiency and predictive capability as compared to slower first-principle based methods, and has the potential to treat the conductance properties of more complex molecular nanojunctions.PACS number(s): 73.63. Nm, 03.65.Fd, 31.15.xf

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Section: Discussionmentioning

confidence: 99%

Electronic conductance via atomic wires: a phase field matching theory approach

Szczęśniak

Khater

2012

Eur. Phys. J. B

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“…In this manner our work appears as a supplementary to the already available studies, but also attempts to visualize discussed effects in the magnetic features of CaC 6 . Such complementary picture may be additionally of great importance for future studies on GICs as well as their purely two-dimensional counterparts like the lithium-decorated graphene [13][14][15][16], which is also predicted to present sizable anisotropy [17,18]. To this end, present work attempts to verify the postulate that six-band model of FS in CaC 6 should be considered as a minimal approximation [2].…”

Section: Introductionmentioning

confidence: 90%

Revealing the anisotropy effects on the critical magnetic field in CaC6 superconductor

2019

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The calcium intercalated graphite (CaC6) is considered to be a representative material of the graphite intercalated superconductors, which exhibits sizable anisotropy of the Fermi surface (FS). Herein, the influence of the FS anisotropy on the critical magnetic field (HC) in CaC6 superconductor is comprehensively analyzed within the Migdal-Eliashberg (M-E) formalism. To precisely account for the mentioned anisotropy effects, the analysis is conducted in the framework of the six-band approximation, hitherto not employed for calculations of the HC function in CaC6 material. For convenience, the obtained results are compared with the available one-and three-band estimates reported by using the M-E theory. A notable signatures of the increased number of bands are observed for the temperature dependent HC functions. In particular, the HC function decreases at T=0 K as the number of the considered bands is higher. Moreover, it is argued that the sixband formalism yields the most physically relevant shape of the HC function among all considered approximations. Therefore, the six-band model introduces not only quantitative but also qualitative changes to the results, in comparison to the other discussed FS approximations. This observation supports postulate that the six-band model constitutes minimal structure for FS of CaC6, but also magnify importance of anisotropy effects for the critical magnetic field calculations.

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“…We do not fit the whole band in order to obtain qualitative agreement with a previous tight-binding calculation reported by Laref et al [41]. A partial fitting of this kind has been used by Szczȩśniak et al [42].…”

Section: Generalized Wannier Functionsmentioning

confidence: 88%

Wannier functions of cumulene: A tight‐binding approach

Ribeiro

Nacbar

Bruno-Alfonso

2015

Physica Status Solidi (b)

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Exponentially localized Wannier functions of cumulene are calculated from the Bloch functions obtained through a tight‐binding approach. Numerical results and discussions are given for the π and σ bands. In the latter case, the single‐band Wannier functions are similar to the orbitals of a diatomic molecule, while the two‐band Wannier functions resemble hybrid atomic orbitals. Contour plot of an sp‐like Wannier function of cumulene.

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Introduction

Cited by 4 publications

References 91 publications

Electronic conductance via atomic wires: a phase field matching theory approach

Electronic conductance via atomic wires: a phase field matching theory approach

Revealing the anisotropy effects on the critical magnetic field in CaC6 superconductor

Wannier functions of cumulene: A tight‐binding approach

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