Spin-polarized electron transport in ferromagnet/semiconductor heterostructures: Unification of ballistic and diffusive transport

Based on MoC2 nanoribbons and poly-(terphenylene-butadiynylene) (PTB) molecules, we designed MoC2-PTB molecular spintronic devices and investigated their spin-dependent electron transport properties by using spin-polarized density functional theory and non-equilibrium Green's...

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Electronic properties of semiconductor quantum wires for shallow symmetric and asymmetric confinements

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/ac3f01 ◽

2021 ◽

Author(s):

Irina I. Yakimenko ◽

Ivan P. Yakimenko

Keyword(s):

Electron Transport ◽

Density Functional ◽

Quantum Wires ◽

Zero Magnetic Field ◽

Electron Interaction ◽

Spin Polarized ◽

Quantum Point ◽

Dimensional Electron Gas ◽

The One ◽

Quantum Technology

Abstract Quantum wires (QWs) and quantum point contacts (QPCs) have been realized in GaAs/AlGaAs heterostructures in which a two-dimensional electron gas (2DEG) resides at the interface between GaAs and AlGaAs layered semiconductors. The electron transport in these structures has previously been studied experimentally and theoretically, and a 0.7 conductance anomaly has been discovered. The present paper is motivated by experiments with a QW in shallow symmetric and asymmetric confinements that have shown additional conductance anomalies at zero magnetic field. The proposed device consists of a QPC that is formed by split gates and a top gate between two large electron reservoirs. This paper is focused on the theoretical study of electron transport through a wide top-gated QPC in a low-density regime and is based on density functional theory. The electron-electron interaction and shallow confinement make the splitting of the conduction channel into two channels possible. Each of them becomes spin-polarized at certain split and top gates voltages and may contribute to conductance giving rise to additional conductance anomalies. For symmetrically loaded split gates two conduction channels contribute equally to conductance. For the case of asymmetrically applied voltage between split gates conductance anomalies may occur between values of 0.25(2e2/h) and 0.7(2e2/h) depending on the increased asymmetry in split gates voltages. This corresponds to different degrees of spin-polarization in the two conduction channels that contribute differently to conductance. In the case of a strong asymmetry in split gates voltages one channel of conduction is pinched off and just the one remaining channel contributes to conductance. We have found that on the perimeter of the anti-dot there are spin-polarized states. These states may also contribute to conductance if the radius of the anti-dot is small enough and tunnelling between these states may occur. The spin-polarized states in the QPC with shallow confinement tuned by electric means may be used for the purposes of quantum technology.

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Spin-Polarized Electron Transport via a C>inf/inf

2006 Sixth IEEE Conference on Nanotechnology ◽

10.1109/nano.2006.1717237 ◽

2006 ◽

Author(s):

Haiying He ◽

R. Pandey ◽

S.P. Karna

Keyword(s):

Electron Transport ◽

Spin Polarized

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Electron Transport Through Epitaxial Metal/Semiconductor Heterostructures

MRS Proceedings ◽

10.1557/proc-77-271 ◽

1986 ◽

Vol 77 ◽

Cited By ~ 4

Author(s):

A. F. J. Levi ◽

R. T. Tung ◽

J. L. Batstone ◽

J. M. Gibson ◽

M. Anzlowar ◽

...

Keyword(s):

Electron Transport ◽

Schottky Barrier ◽

Semiconductor Heterostructures ◽

Perfect Single Crystal ◽

Barrier Heights ◽

Semiconductor Interfaces ◽

Semiconductor Contacts ◽

First Time ◽

Silicon Heterostructures

ABSTRACTAbrupt, epitaxial silicide/silicon heterostructures may be grown so that, for the first time, the physics of electron transport across near perfect, single crystal, metal/semiconductor interfaces may be probed experimentally. Transport measurements through type-A and -B oriented NiSi2 layers on Si(111) substrates have revealed Schottky barrier heights differing by 140 meV. In this paper we present results of experiments designed to explore the possible role of bulk and interface defects in determining the potential barrier at these near ideal epitaxial metal-semiconductor contacts. We have found little evidence for the presence of defects and the Schottky barrier is insensitive to details of the microscopic interfacial perfection. By contrast we find that both the electrical quality and magnitude of the barrier occurring at the NiSi2 /Si(100) heterojunction are dependent upon details of the microscopic interfacial perfection.

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Spin-polarized electron transport and emission from strained superlattices

10.1117/12.417689 ◽

2001 ◽

Author(s):

Yuri A. Mamaev ◽

Arsen V. Subashiev ◽

Yuri P. Yashin ◽

Anton N. Ambrajei ◽

Alexander V. Roschansky

Keyword(s):

Electron Transport ◽

Spin Polarized

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Perfect spin-filter devices based on zigzag zinc oxide nanoribbons

Modern Physics Letters B ◽

10.1142/s0217984916503929 ◽

2016 ◽

Vol 30 (32n33) ◽

pp. 1650392 ◽

Cited By ~ 2

Author(s):

Zi-Yue Zhang

Keyword(s):

Zinc Oxide ◽

Electron Transport ◽

Spin Polarization ◽

Bias Voltage ◽

First Principles ◽

External Fields ◽

Spin Filter ◽

Spin Polarized ◽

Spin Filters ◽

Filtering Effect

Spin-polarized electron transport through a zigzag zinc oxide nanoribbon (ZnONR) has been studied using first-principles transport simulations. Ribbons without edges passivated show 100% spin polarization at small bias voltage independently of width. The ribbons with edge zinc atoms passivated maintain absolute spin-filtering effect in much larger bias region. The results demonstrate that zigzag ZnONRs act as perfect spin-filters in the absence of magnetic electrodes and external fields.

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