Theory of Quantum Transport at Nanoscale

Ryndyk, Dmitry A.

doi:10.1007/978-3-319-24088-6

Cited by 103 publications

(109 citation statements)

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“…Their matrix elements are the broadening coefficients Γ's, which describe the coupling between the molecule and the contacts. 40 When the contacts are metallic, we can take the wide-band limit since their density of states are flat. Thus, the Γ's are simply given by a constant, which we take as the energy unit: Γ L µ1σ,µ1σ = Γ R νN s,νN s = Γ 0 = 1 (µ, ν = A, B, and σ, s =↑, ↓).…”

Section: Transmission and Spin Polarizationmentioning

confidence: 99%

Spin-Polarized Electron Transmission in DNA-Like Systems

et al. 2019

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The helical distribution of the electronic density in chiral molecules, such as DNA and bacteriorhodopsin, has been suggested to induce a spin-orbit coupling interaction that may lead to the so-called chirality-induced spin selectivity (CISS) effect. Key ingredients for the theoretical modelling are, in this context, the helically shaped potential of the molecule and, concomitantly, a Rashba-like spin-orbit coupling due to the appearance of a magnetic field in the electron reference frame. Symmetries of these models clearly play a crucial role in explaining the observed effect, but a thorough analysis has been largely ignored in the literature. In this work, we present a study of these symmetries and how they can be exploited to enhance chiral-induced spin selectivity in helical molecular systems.

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Section: Transmission and Spin Polarizationmentioning

confidence: 99%

Spin-Polarized Electron Transmission in DNA-Like Systems

et al. 2019

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“…In fact, Fisher-Lee's equation is simply recovered by substituting the multiple-scattering renormalized propagators by their zeroth order approximation, i.e. by replacing D by the identity matrix, which is valid if the perturbation between the collector and the injector is weak [22,23] …”

Section: Theoretical Approachmentioning

confidence: 99%

Electron transport in ultra-thin films and ballistic electron emission microscopy

Claveau

Matteo

Andrés

2017

J. Phys.: Condens. Matter

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Abstract. We have developed a calculation scheme for the elastic electron current in ultra-thin epitaxial heterostructures. Our model uses a Keldysh's non-equilibrium Green's function formalism and a layer-by-layer construction of the epitaxial film. Such an approach is appropriate to describe the current in a Ballistic Electron Emission Microscope (BEEM) where the metal base layer is ultra-thin and generalizes a previous one based on a decimation technique appropriated for thick slabs. This formalism allows a full quantum mechanical description of the transmission across the epitaxial heterostructure interface, including multiple scattering via the Dyson equation, which is deemed a crucial ingredient to describe interfaces of ultra-thin layers properly in the future.We introduce a theoretical formulation needed for ultra-thin layers and we compare with results obtained for thick Au(111) metal layers. An interesting effect takes place for a width of about ten layers: a BEEM current can propagate via the center of the reciprocal space (Γ) along the Au(111) direction. We associate this current to a coherent interference finite-width effect that cannot be found using a decimation technique. Finally, we have tested the validity of the handy semiclassical formalism to describe the BEEM current.

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“…The conductance is one of the most important properties of a material, which is also very susceptible to quantum effects caused by miniaturization. Theoretically, the conductance () G for quantum systems in the nanoscale can be calculated from the Landauer formula [1] 2 e GT  = (1) where T is the transmission coefficient for single-channel systems or the transmission function in multi-channel ones [2]. For Layered composed systems, fast techniques to determine the Landauer conductance based on the transfer matrix approach have been widely used [3][4][5][6][7][8], where the wavefunction behavior is iteratively obtained by means of multiplications of transfer matrixes.…”

Section: Introductionmentioning

confidence: 99%

“…shows the effective transmission function (T), defined as the summation of the transmittances from the left to the right lead[2], for the system inFig. 5(b)when all selfenergies are zero and hopping integrals are t , (a) that in all cases leads are connected by an atomic-chain that have extended states only if 2 Et …”

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confidence: 99%

Scattering matrix of arbitrary tight-binding Hamiltonians

García

Medina-Amayo

2017

Annals of Physics

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A novel efficient method to calculate the scattering matrix (SM) of arbitrary tight-binding Hamiltonians is proposed, including cases with multiterminal structures. In particular, the SM of two kind of fundamental structures are given, which can be used to obtain the SM of bigger systems iteratively. Also, a procedure to obtain the SM of layer-composed periodic leads is described. This method allows renormalization approaches, which permits computations over macroscopic length systems without introducing additional approximations. Finally, the transmission coefficient of a ring-shaped multiterminal system and the transmission function of a square-lattice nanoribbon with a reduced width region are calculated.

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Theory of Quantum Transport at Nanoscale

Cited by 103 publications

References 0 publications

Spin-Polarized Electron Transmission in DNA-Like Systems

Spin-Polarized Electron Transmission in DNA-Like Systems

Electron transport in ultra-thin films and ballistic electron emission microscopy

Scattering matrix of arbitrary tight-binding Hamiltonians

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