scholarly journals Tunable dispersion of the edge states in the integer quantum Hall effect

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
Maik Malki ◽  
Götz Uhrig
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Condensed Matter ◽  
Quantum Hall ◽  
External Control ◽  
Fermi Velocity ◽  
Control Parameters ◽  
Edge States ◽  
Integer Quantum Hall Effect ◽  
Integer Quantum

Topological aspects represent currently a boosting area in condensed matter physics. Yet there are very few suggestions for technical applications of topological phenomena. Still, the most important is the calibration of resistance standards by means of the integer quantum Hall effect. We propose modifications of samples displaying the integer quantum Hall effect which render the tunability of the Fermi velocity possible by external control parameters such as gate voltages. In this way, so far unexplored possibilities arise to realize devices such as tunable delay lines and interferometers.

Current-induced decoupling of edge states in the integer quantum Hall effect

1996 ◽  
Vol 54 (20) ◽  
pp. R14261-R14264 ◽  
Author(s):  
T. Machida ◽  
H. Hirai ◽  
S. Komiyama ◽  
T. Osada ◽  
Y. Shiraki
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Edge States ◽  
Integer Quantum Hall Effect ◽  
Integer Quantum

scholarly journals Edge probes of topological order

2020 ◽  
Vol 35 (18) ◽  
pp. 2030009 ◽  
Author(s):  
Moty Heiblum ◽  
D. E. Feldman
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Experimental Techniques ◽  
Topological Order ◽  
Edge States ◽  
Integer Quantum Hall Effect ◽  
Noise Measurements ◽  
Integer Quantum ◽  
Dimensional Electron Gas

According to the bulk-edge correspondence principle, the physics of the gapless edge in the quantum Hall effect determines the topological order in the gapped bulk. As the bulk is less accessible, the last two decades saw the emergence of several experimental techniques that invoke the study of the compressible edge. We review the properties of the edge, and describe several experimental techniques that include shot noise and thermal noise measurements, interferometry, and energy (thermal) transport at the edge. We pay special attention to the filling factor 5/2 in the first excited Landau level (in two-dimensional electron gas in GaAs), where experimental evidence of a non-Abelian topological order was found. A brief discussion is devoted to recent interferometry experiments that uncovered unexpected physics in the integer quantum Hall effect. The article also addresses the theory of edge states, for systems with Abelian and non-Abelian topological orders.

scholarly journals An all-epitaxial nitride heterostructure with concurrent quantum Hall effect and superconductivity

2021 ◽  
Vol 7 (8) ◽  
pp. eabf1388
Author(s):  
Phillip Dang ◽  
Guru Khalsa ◽  
Celesta S. Chang ◽  
D. Scott Katzer ◽  
Neeraj Nepal ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Electron Gas ◽  
Quantum Hall ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
2D Electron Gas ◽  
Integer Quantum Hall Effect ◽  
Topological Quantum ◽  
Integer Quantum

Creating seamless heterostructures that exhibit the quantum Hall effect and superconductivity is highly desirable for future electronics based on topological quantum computing. However, the two topologically robust electronic phases are typically incompatible owing to conflicting magnetic field requirements. Combined advances in the epitaxial growth of a nitride superconductor with a high critical temperature and a subsequent nitride semiconductor heterostructure of metal polarity enable the observation of clean integer quantum Hall effect in the polarization-induced two-dimensional (2D) electron gas of the high-electron mobility transistor. Through individual magnetotransport measurements of the spatially separated GaN 2D electron gas and superconducting NbN layers, we find a small window of magnetic fields and temperatures in which the epitaxial layers retain their respective quantum Hall and superconducting properties. Its analysis indicates that in epitaxial nitride superconductor/semiconductor heterostructures, this window can be significantly expanded, creating an industrially viable platform for robust quantum devices that exploit topologically protected transport.

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