Quantum Transport Methodologies for Spin Transport

Effect of Twisting and Stretching on Magneto Resistance and Spin Filtration in CNTs

10.20944/preprints201704.0095.v1 ◽

2017 ◽

Author(s):

Anil Kumar Singh ◽

Sudhanshu Choudhary

Keyword(s):

Density Functional Theory ◽

Carbon Nanotube ◽

Transport Properties ◽

Quantum Transport ◽

Density Functional ◽

Spin Transport ◽

Functional Theory ◽

Higher Spin ◽

High Bias ◽

Magneto Resistance

Spin dependent quantum transport properties in twisted carbon nanotube and stretched carbon nanotube are calculated using density functional theory (DFT) and non-equilibrium green’s function (NEGF) formulation. Twisting and stretching have no effect on spin transport in CNTs at low bias voltages. However, at high bias voltages the effects are significant. Stretching restricts any spin-up current in antiparallel configuration (APC) which results in higher magneto resistance (MR). Twisting allows spin-up current almost equivalent to the pristine CNT case resulting in lower MR. High spin filtration is observed in PC and APC for pristine, stretched and twisted structures at all applied voltages. In APC, at low voltages spin filtration in stretched CNT is higher than in pristine and twisted ones with pristine giving higher spin filtration than twisted CNT.

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Effects of Rashba spin–orbit coupling on the conductance of graphene-based nanoribbons

International Journal of Modern Physics B ◽

10.1142/s0217979217500436 ◽

2017 ◽

Vol 31 (06) ◽

pp. 1750043 ◽

Cited By ~ 1

Author(s):

Zeinab Rashidian ◽

Parvin Bayati ◽

Zeinab Lorestaniwiess

Keyword(s):

Quantum Transport ◽

Spin Transport ◽

Orbit Coupling ◽

Monolayer Graphene ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Zigzag Edge ◽

Transmission Properties ◽

Rashba Spin ◽

Different Types

The transmission properties of armchair- and zigzag-edged graphene nanoribbon junctions between graphene electrodes are examined by means of the standard nonequilibrium Green’s function (NEGF) technique. The quantum transport of electrons is studied through a monolayer graphene strip in the presence of Rashba spin–orbit coupling that acts as a barrier between the two normal leads. The present work compares the conductances of nanoribbons with zigzag and armchair edges. Since the nature of induced gap for zigzag edge is different from armchair, it is expected to give rise to different types of conductance for each edge. Findings indicate that the Rashba strength has more pronounced influence on armchair ribbons than on zigzag ribbons, and the minimum conductance of [Formula: see text] for nanoribbon remains intact even in the presence of the Rashba spin–orbit coupling. It is predicted that controllability of spin transport in the monolayer graphene may contribute to the development of well-known spintronics.

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Spin Transport and Spin Conversion at Room Temperature in Exotic Materials Systems

The Journal of the Institute of Electrical Engineers of Japan ◽

10.1541/ieejjournal.139.668 ◽

2019 ◽

Vol 139 (10) ◽

pp. 668-673

Author(s):

Masashi SHIRAISHI

Keyword(s):

Room Temperature ◽

Spin Transport ◽

Spin Conversion

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Single-band quantum transport study of resonant tunneling diodes based on silicene nanoribbons

2020 43rd International Convention on Information, Communication and Electronic Technology (MIPRO) ◽

10.23919/mipro48935.2020.9245394 ◽

2020 ◽

Author(s):

M. Mihaljevic ◽

M. Siric ◽

M. Poljak

Keyword(s):

Quantum Transport ◽

Resonant Tunneling ◽

Single Band ◽

Resonant Tunneling Diodes ◽

Tunneling Diodes ◽

Transport Study ◽

Silicene Nanoribbons

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Quantum Transport in Si:P δ-Layer Wires

2020 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) ◽

10.23919/sispad49475.2020.9241610 ◽

2020 ◽

Author(s):

Juan P. Mendez ◽

Denis Mamaluy ◽

Xujiao Gao ◽

Evan M. Anderson ◽

DeAnna M. Campbell ◽

...

Keyword(s):

Quantum Transport

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Nonequilibrium Green’s Functions

10.1093/oso/9780198797241.003.0007 ◽

2018 ◽

Author(s):

Klaus Morawetz

Keyword(s):

Green’S Function ◽

Quantum Transport ◽

Green's Function ◽

Green's Functions ◽

Green’S Functions ◽

Equation Of Motion ◽

Diagrammatic Technique ◽

Initial Correlations ◽

Nonequilibrium Green’S Functions ◽

Nonequilibrium Green's Functions

The method of the equation of motion is used to derive the Martin–Schwinger hierarchy for the nonequilibrium Green’s functions. The formal closure of the hierarchy is reached by using the selfenergy which provides a recipe for how to construct selfenergies from approximations of the two-particle Green’s function. The Langreth–Wilkins rules for a diagrammatic technique are shown to be equivalent to the weakening of initial correlations. The quantum transport equations are derived in the general form of Kadanoff and Baym equations. The information contained in the Green’s function is discussed. In equilibrium this leads to the Matsubara diagrammatic technique.

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