scholarly journals Quantum Hall effect in a bulk antiferromagnet EuMnBi2 with magnetically confined two-dimensional Dirac fermions

2016 ◽  
Vol 2 (1) ◽  
pp. e1501117 ◽  
Author(s):  
Hidetoshi Masuda ◽  
Hideaki Sakai ◽  
Masashi Tokunaga ◽  
Yuichi Yamasaki ◽  
Atsushi Miyake ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Magnetic Order ◽  
Quantum Hall ◽  
High Mobility ◽  
Interlayer Coupling ◽  
Dirac Fermions ◽  
Energy Excitation ◽  
Integer Quantum Hall Effect ◽  
Dirac Materials

For the innovation of spintronic technologies, Dirac materials, in which low-energy excitation is described as relativistic Dirac fermions, are one of the most promising systems because of the fascinating magnetotransport associated with extremely high mobility. To incorporate Dirac fermions into spintronic applications, their quantum transport phenomena are desired to be manipulated to a large extent by magnetic order in a solid. We report a bulk half-integer quantum Hall effect in a layered antiferromagnet EuMnBi2, in which field-controllable Eu magnetic order significantly suppresses the interlayer coupling between the Bi layers with Dirac fermions. In addition to the high mobility of more than 10,000 cm2/V s, Landau level splittings presumably due to the lifting of spin and valley degeneracy are noticeable even in a bulk magnet. These results will pave a route to the engineering of magnetically functionalized Dirac materials.

scholarly journals Half integer quantum Hall effect in high mobility single layer epitaxial graphene

2009 ◽  
Vol 95 (22) ◽  
pp. 223108 ◽  
Author(s):  
Xiaosong Wu ◽  
Yike Hu ◽  
Ming Ruan ◽  
Nerasoa K Madiomanana ◽  
John Hankinson ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
High Mobility ◽  
Single Layer ◽  
Epitaxial Graphene ◽  
Half Integer ◽  
Integer Quantum Hall Effect ◽  
Integer Quantum

INHOMOGENEITY OF ELECTRON LIQUID AND EFFECTS OF INTERLAYER COUPLING IN GaAs/AlGaAs SUPERLATTICES IN THE REGIME OF THE QUANTUM HALL EFFECT

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1409-1413
Author(s):  
Y. A. PUSEP ◽  
F. E. G. GUIMARÃES ◽  
H. ARAKAKI ◽  
C. A. DE SOUZA ◽  
A. J. CHIQUITO
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Filling Factor ◽  
Quantum Hall ◽  
Interlayer Coupling ◽  
Integer Quantum Hall Effect ◽  
Weakly Coupled ◽  
Integer Quantum ◽  
Increasing Temperature ◽  
Partial Population

Formation of the electron state with the integer filling factor was studied by magneto-capacitance and magneto-photoluminescence measurements in weakly coupled GaAs/AlGaAs multilayers where quasi-two dimensional electrons revealed the integer Quantum Hall Effect. The disorder modulated compressibility of the quantized Hall phase with the filling factor ν=2 was determined. The incompressible fraction of this phase was shown to rapidly disappear with the increasing temperature. The quantized Hall phase of the weakly coupled multilayers was shown to emit the asymmetrical photoluminescence lines. We demonstrated that the observed asymmetry is caused by a partial population of the extended electron states formed in the quantized Hall conductor phase due to the disorder induced interlayer tunneling.

scholarly journals Half-integer quantum Hall effect of disordered Dirac fermions at a topological insulator surface

2014 ◽  
Vol 90 (16) ◽  
Author(s):  
E. J. König ◽  
P. M. Ostrovsky ◽  
I. V. Protopopov ◽  
I. V. Gornyi ◽  
I. S. Burmistrov ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Topological Insulator ◽  
Quantum Hall ◽  
Dirac Fermions ◽  
Insulator Surface ◽  
Half Integer ◽  
Integer Quantum Hall Effect ◽  
Integer Quantum

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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