Magnetotransport in organic Dirac fermion system at the quantum limit: Interlayer Hall effect and surface transport via helical edge states

2012 ◽  
Vol 249 (5) ◽  
pp. 962-966 ◽  
Author(s):  
Toshihito Osada
Keyword(s):  
Hall Effect ◽  
Quantum Limit ◽  
Dirac Fermion ◽  
Edge States ◽  
Fermion System ◽  
Surface Transport

Magnetocapacitance Investigation of Quantum Hall Effect and Edge States

1997 ◽  
Vol 11 (22) ◽  
pp. 2593-2619 ◽  
Author(s):  
Sadao Takaoka ◽  
Kenichi Oto ◽  
Kazuo Murase
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Electron System ◽  
Edge Length ◽  
Capacitance Measurement ◽  
Edge States ◽  
Bulk Conductivity ◽  
Cyclotron Radius ◽  
Bulk State

The quantum Hall effect for the GaAs/AlGaAs heterostrcture is investigated by an ac capacitance measurement between the two-dimensional electron system (2DES) and the gate on GaAs/AlGaAs. The capacitance minima at the quantum Hall plateaus are mainly determined not by the 2DES area under the gate but by the edge length of 2DES. There exists the high conductive region due to the edge states along the 2DES boundary, when the bulk conductivity σxx is small enough at low temperatures and high magnetic fields. From the temperature and frequency dependence of the capacitance minima, it is found that the measured capacitance consists of the contribution from the edge states and that of the bulk state, which is treated as a distributed circuit of a resistive plate with the conductivity σxx. The evaluated width of edge states from the capacitance is much larger than the magnetic length and the cyclotron radius expected from the one-electron picture. This wide width of edge states can be explained by the compressible-incompressible strip model, in which the screening effect is taken into account. Further the bulk conductivity of less than 10-12 S (S=1/Ω) is measured by the capacitance of the Corbino geometry sample, where the edge states are absent and the capacitance is determined by only σxx in this geometry. The localization of the bulk state is investigated by the obtained σxx.

VERTEX OPERATORS IN THE QUANTUM HALL EFFECT

1991 ◽  
Vol 05 (03) ◽  
pp. 509-527 ◽  
Author(s):  
MICHAEL STONE
Keyword(s):  
Hall Effect ◽  
Landau Level ◽  
Quantum Hall Effect ◽  
Group Action ◽  
Quantum Hall ◽  
Vertex Operators ◽  
Edge States ◽  
Many Body ◽  
Level I ◽  
The Many

The edge states of the quantum Hall effect carry representations of chiral current algebras and their associated groups. In the simplest case of a single filled Landau level, I demonstrate explicitly how the group action affects the many-body states, and why the Kac-Peterson cocycle appears in the group multiplication law. I show how these representations may be used to construct vertex operators which create localised edge excitations, and indicate how they are related to the bulk quasi-particles.

scholarly journals Pressure-induced phase switching of Shubnikov–de Haas oscillations in the molecular Dirac fermion system α−(BETS)2I3

2021 ◽  
Vol 103 (20) ◽  
Author(s):  
Yoshitaka Kawasugi ◽  
Hikaru Masuda ◽  
Masashi Uebe ◽  
Hiroshi M. Yamamoto ◽  
Reizo Kato ◽  
...  
Keyword(s):  
Dirac Fermion ◽  
Fermion System ◽  
Phase Switching ◽  
Shubnikov De Haas Oscillations

scholarly journals Transport Phenomena in Multilayered Massless Dirac Fermion System α-(BEDT-TTF)2I3

Crystals ◽  
2012 ◽  
Vol 2 (2) ◽  
pp. 643-661 ◽  
Author(s):  
Naoya Tajima ◽  
Yutaka Nishio ◽  
Koji Kajita
Keyword(s):  
Transport Phenomena ◽  
Dirac Fermion ◽  
Fermion System ◽  
Massless Dirac Fermion

scholarly journals Progress Review on Topological Properties of Heusler Materials

2020 ◽  
Vol 213 ◽  
pp. 02016
Author(s):  
Zhi Lin
Keyword(s):  
Hall Effect ◽  
Surface States ◽  
Anomalous Hall Effect ◽  
Edge State ◽  
Chiral Anomaly ◽  
Dirac Fermion ◽  
High Symmetry ◽  
Heusler Compounds ◽  
Topological Properties ◽  
Topological State

Starting from crystal, electronic and magnetic structures of Heusler compounds, this paper studies the new topological materials related to Heusler compounds and their topological properties, such as anomalous Hall effect, skyrmions, chiral anomaly, Dirac fermion, Weyl fermion, transverse Nernst thermoelectric effect, thermal spintronics and topological surface states. It can be discovered that the topological state of Heusler compound can be well protected due to its high symmetry, thus producing rich topological properties. Heusler materials belonged to Weyl semimetals usually have strong anomalous Hall effect, and the Heusler materials with doping or Anomalous Nernst Effect (ANE) usually have higher thermoelectric figure of merit. These anomalous effects are closely related to the strong spin–orbit interaction. In application, people can use the non-dissipative edge state of quantum anomalous Hall effect to develop a new generation of low-energy transistors and electronic devices. The conversion efficiency of thermoelectric materials can be improved by ANE, and topological superconductivity can be used to promote the progress of quantum computation.

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