scholarly journals Separately contacted edge states: A spectroscopic tool for the investigation of the quantum Hall effect

2002 ◽  
Vol 65 (7) ◽  
Author(s):  
A. Würtz ◽  
R. Wildfeuer ◽  
A. Lorke ◽  
E. V. Deviatov ◽  
V. T. Dolgopolov
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Edge States ◽  
Spectroscopic Tool

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 Quantum parity Hall effect in Bernal-stacked trilayer graphene

2019 ◽  
Vol 116 (21) ◽  
pp. 10286-10290 ◽  
Author(s):  
Petr Stepanov ◽  
Yafis Barlas ◽  
Shi Che ◽  
Kevin Myhro ◽  
Greyson Voigt ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Exchange Interactions ◽  
Mirror Reflection ◽  
Edge States ◽  
State Variables ◽  
Coulomb Interactions ◽  
Spin Polarized ◽  
Trilayer Graphene

The quantum Hall effect has recently been generalized from transport of conserved charges to include transport of other approximately conserved-state variables, including spin and valley, via spin- or valley-polarized boundary states with different chiralities. Here, we report a class of quantum Hall effect in Bernal- or ABA-stacked trilayer graphene (TLG), the quantum parity Hall (QPH) effect, in which boundary channels are distinguished by even or odd parity under the system’s mirror reflection symmetry. At the charge neutrality point, the longitudinal conductance σxx is first quantized to 4e2/h at a small perpendicular magnetic field B⊥, establishing the presence of four edge channels. As B⊥ increases, σxx first decreases to 2e2/h, indicating spin-polarized counterpropagating edge states, and then, to approximately zero. These behaviors arise from level crossings between even- and odd-parity bulk Landau levels driven by exchange interactions with the underlying Fermi sea, which favor an ordinary insulator ground state in the strong B⊥ limit and a spin-polarized state at intermediate fields. The transitions between spin-polarized and -unpolarized states can be tuned by varying Zeeman energy. Our findings demonstrate a topological phase that is protected by a gate-controllable symmetry and sensitive to Coulomb interactions.

scholarly journals Quantum Hall effect on S3, edge states and fuzzy

2004 ◽  
Vol 679 (3) ◽  
pp. 447-463 ◽  
Author(s):  
V.P. Nair ◽  
S. Randjbar-Daemi
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Edge States

Quantum hall effect and edge states in (TMTSF)2PF6

1999 ◽  
Vol 103 (1-3) ◽  
pp. 2113-2114
Author(s):  
J.B. Young ◽  
H. Cho ◽  
S.T. Hannahs ◽  
W. Kang
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Edge States

THE QUANTUM HALL EFFECT IN QUASI-ONE-DIMENSIONAL ORGANIC CONDUCTORS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3089-3089
Author(s):  
V. M. YAKOVENKO
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Organic Conductors ◽  
Temperature Evolution ◽  
Edge States ◽  
One Dimensional ◽  
Recent Developments ◽  
Theoretical Overview

Theoretical overview of the quantum Hall effect in quasi-one-dimensional (Q1D) organic conductors (TMTSF) 2 X will be presented.1 The emphasis will be on the recent developments, such as the temperature evolution of the Hall effect2,3 and the chiral edge states.4 Time permitting, a theory of the nonchiral electron edge states in a Q1D triplet superconductor5 and the holon edge states in the charge-gap regime6 will be presented too.

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