scholarly journals Electron tunneling through double magnetic barriers on the surface of a topological insulator

2010 ◽  
Vol 82 (11) ◽  
Author(s):  
Zhenhua Wu ◽  
F. M. Peeters ◽  
Kai Chang
Keyword(s):  
Topological Insulator ◽  
Electron Tunneling ◽  
Magnetic Barriers

Electron tunneling of graphene modulated by realistic magnetic barriers

2015 ◽  
Vol 379 (34-35) ◽  
pp. 1906-1911 ◽  
Author(s):  
Wei-Tao Lu ◽  
Chang-Tan Xu ◽  
Cheng-Zhi Ye ◽  
Hua Jiang ◽  
Hong-Zhe Pan ◽  
...  
Keyword(s):  
Electron Tunneling ◽  
Magnetic Barriers

Electronic tunneling through a potential barrier on the surface of a topological insulator

2016 ◽  
Vol 30 (35) ◽  
pp. 1650416
Author(s):  
Benliang Zhou ◽  
Benhu Zhou ◽  
Guanghui Zhou
Keyword(s):  
Potential Barrier ◽  
Topological Insulator ◽  
Electron Tunneling ◽  
Oscillation Amplitude ◽  
Transmission Probability ◽  
Incident Electron Energy ◽  
Barrier Width ◽  
Directional Filtering ◽  
Electronic Tunneling ◽  
Tunneling Transport

We investigate the tunneling transport for electrons on the surface of a topological insulator (TI) through an electrostatic potential barrier. By using the Dirac equation with the continuity conditions for all segments of wave functions at the interfaces between regions inside and outside the barrier, we calculate analytically the transmission probability and conductance for the system. It is demonstrated that, the Klein paradox can also been observed in the system same as in graphene system. Interestingly, the conductance reaches the minimum value when the incident electron energy is equal to the barrier strength. Moreover, with increasing barrier width, the conductance turns up some tunneling oscillation peaks, and larger barrier strength can cause lower conductance, shorter period but larger oscillation amplitude. The oscillation amplitude decreases as the barrier width increases, which is similar as that of the system consisting of the compressive uniaxial strain applied on a TI, but somewhat different from that of graphene system where the oscillation amplitude is a constant. The findings here imply that an electrostatic barrier can greatly influence the electron tunneling transport of the system, and may provide a new way to realize directional filtering of electrons.

scholarly journals Quasistationary states in a quantum dot formed at the edge of a topological insulator by magnetic barriers with finite transparency

2021 ◽  
Vol 2103 (1) ◽  
pp. 012201
Author(s):  
D V Khomitsky ◽  
E A Lavrukhina
Keyword(s):  
Topological Insulator ◽  
Two Dimensional ◽  
Edge States ◽  
Stationary Schrödinger Equation ◽  
Double Barrier ◽  
One Dimensional ◽  
Occupation Numbers ◽  
The One ◽  
Magnetic Barriers ◽  
Double Barrier Structure

Abstract A model of quasistationary states is constructed for the one-dimensional edge states propagating along the edge of a two-dimensional topological insulator based on HgTe/CdTe quantum well in the presence of magnetic barriers with finite transparency. The lifetimes of these quasistationary states are found analytically and numerically via different approaches including the solution of the stationary Schrödinger equation with complex energy and the solution of the transmission problem for a double barrier structure. The results can serve as a guide for determining the parameters of magnetic barriers creating the quantum dots where the lifetimes for the broadened discrete levels are long enough for manipulation with their occupation numbers by external fields.

scholarly journals Fabry-Pérot resonant vortices and magnetoconductance in topological insulator constrictions with magnetic barriers

2021 ◽  
Vol 103 (20) ◽  
Author(s):  
R. P. Maciel ◽  
A. L. Araújo ◽  
C. H. Lewenkopf ◽  
G. J. Ferreira
Keyword(s):  
Topological Insulator ◽  
Fabry Perot ◽  
Magnetic Barriers

A TEM study of electron tunneling in biological macromolecules

1987 ◽  
Vol 45 ◽  
pp. 140-141
Author(s):  
J. A. Panitz
Keyword(s):  
Stark Effect ◽  
Electron Tunneling ◽  
Imaging Modality ◽  
Tunneling Current ◽  
Biological Species ◽  
Scanning Tunneling ◽  
Biological Macromolecules ◽  
Flat Surfaces ◽  
Virus Particles ◽  
Stm Images

Tunneling is a ubiquitous phenomenon. Alpha particle disintegration, the Stark effect, superconductivity in thin films, field-emission, and field-ionization are examples of electron tunneling phenomena. In the scanning tunneling microscope (STM) electron tunneling is used as an imaging modality. STM images of flat surfaces show structure at the atomic level. However, STM images of large biological species deposited onto flat surfaces are disappointing. For example, unstained virus particles imaged in the STM do not resemble their TEM counterparts.It is not clear how an STM image of a biological species is formed. Most biological species are large compared to the nominal electrode separation of ∼ 1nm that is required for electron tunneling. To form an image of a biological species, the tunneling electrodes must be separated by a distance that would normally be too large for a tunneling current to be observed.

Field-assisted ionization theory for microscopists

1994 ◽  
Vol 52 ◽  
pp. 820-821
Author(s):  
Patrick P. Camus
Keyword(s):  
Electric Field ◽  
Electron Tunneling ◽  
Ionization Probability ◽  
Critical Distance ◽  
Tunneling Probability ◽  
Field Ionization ◽  
Radius Of Curvature ◽  
Field Evaporation ◽  
A Value ◽  
Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

Sensing of dynamic charge states using single-electron tunneling transistors

1998 ◽  
Vol 168 (2) ◽  
pp. 219
Author(s):  
V.A. Krupenin ◽  
S.V. Lotkhov ◽  
H. Scherer ◽  
A.B. Zorin ◽  
F.-J. Ahlers ◽  
...  
Keyword(s):  
Electron Tunneling ◽  
Single Electron ◽  
Single Electron Tunneling ◽  
Dynamic Charge ◽  
Charge States
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