Real-space and magnetic-field correlation of quantum-resistance fluctuations in the ballistic regime in narrow GaAs-AlxGa1−xAs wires

1988 ◽  
Vol 37 (5) ◽  
pp. 2745-2748 ◽  
Author(s):  
A. M. Chang ◽  
G. Timp ◽  
J. E. Cunningham ◽  
P. M. Mankiewich ◽  
R. E. Behringer ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Real Space ◽  
Ballistic Regime ◽  
Field Correlation ◽  
Resistance Fluctuations

scholarly journals TRANSPORT PROPERTIES OF 2D ELECTRON GAS IN AN n-InGaAs/GaAs DQW IN A VICINITY OF LOW MAGNETIC-FIELD-INDUCED HALL INSULATOR–QUANTUM HALL LIQUID TRANSITION

2007 ◽  
Vol 06 (03n04) ◽  
pp. 173-177
Author(s):  
YU. G. ARAPOV ◽  
S. V. GUDINA ◽  
G. I. HARUS ◽  
V. N. NEVEROV ◽  
N. G. SHELUSHININA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Gas ◽  
Quantum Hall ◽  
Zero Magnetic Field ◽  
Double Quantum ◽  
Ballistic Regime ◽  
2D Electron Gas ◽  
Double Quantum Well ◽  
Liquid Transition ◽  
Low Magnetic Field

The resistivity (ρ) of low mobility dilute 2D electron gas in an n- InGaAs / GaAs double quantum well (DQW) exhibits the monotonic "insulating-like" temperature dependence (dρ/dT < 0) at T = 1.8–70 K in zero magnetic field. This temperature interval corresponds to a ballistic regime (kBTτ/ħ > 0.1–3.5) for our samples, and the electron density is on an "insulating" side of the so-called B = 0 2D metal–insulator transition. We show that the observed features of localization and Landau quantization in a vicinity of the low magnetic-field-induced insulator–quantum Hall liquid transition is due to the σxy(T) anomalous T-dependence.

scholarly journals Giant magnetic field from moiré induced Berry phase in homobilayer semiconductors

2019 ◽  
Vol 7 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Hongyi Yu ◽  
Mingxing Chen ◽  
Wang Yao
Keyword(s):  
Magnetic Field ◽  
Berry Phase ◽  
Transition Metal Dichalcogenides ◽  
Real Space ◽  
Quantum Spin ◽  
Moire Patterns ◽  
Metal Dichalcogenides ◽  
Berry Phases ◽  
Different Origins ◽  
Moiré Patterns

Abstract When quasiparticles move in condensed matters, the texture of their internal quantum structure as a function of position and momentum can give rise to Berry phases that have profound effects on the material’s properties. Seminal examples include the anomalous Hall and spin Hall effects from the momentum-space Berry phases in homogeneous crystals. Here, we explore a conjugate form of the electron Berry phase arising from the moiré pattern: the texture of atomic configurations in real space. In homobilayer transition metal dichalcogenides, we show that the real-space Berry phase from moiré patterns manifests as a periodic magnetic field with magnitudes of up to hundreds of Tesla. This quantity distinguishes moiré patterns from different origins, which can have an identical potential landscape, but opposite quantized magnetic flux per supercell. For low-energy carriers, the homobilayer moirés realize topological flux lattices for the quantum-spin Hall effect. An interlayer bias can continuously tune the spatial profile of the moiré magnetic field, whereas the flux per supercell is a topological quantity that can only have a quantized jump observable at a moderate bias. We also reveal the important role of the non-Abelian Berry phase in shaping the energy landscape in small moiré patterns. Our work points to new possibilities to access ultra-high magnetic fields that can be tailored to the nanoscale by electrical and mechanical controls.

scholarly journals Temperature and Magnetic-Field-Enhanced Hall Slope of a Dilute 2D Hole System in the Ballistic Regime

2004 ◽  
Vol 93 (25) ◽  
Author(s):  
X. P. A. Gao ◽  
G. S. Boebinger ◽  
A. P. Mills ◽  
A. P. Ramirez ◽  
L. N. Pfeiffer ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Ballistic Regime

Theory and observations of switchbacks’ evolution in the solar wind

2021 ◽  
Author(s):  
Anna Tenerani ◽  
Marco Velli ◽  
Lorenzo Matteini
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Radial Magnetic Field ◽  
Open Questions ◽  
Coronal Activity ◽  
Turbulent Heating ◽  
Field Lines ◽  
Radial Evolution ◽  
Field Correlation

&lt;p&gt;Alfv&amp;#233;nic fluctuations represent the dominant contributions to turbulent fluctuations in the solar wind, especially, but not limited to, the fastest streams with velocity of the order of 600-700 km/s. Alfv&amp;#233;nic fluctuations can contribute to solar wind heating and acceleration via wave pressure and turbulent heating. Observations show that such fluctuations are characterized by a nearly constant magnetic field amplitude, a condition which remains largely to be understood and that may be an indication of how fluctuations evolve and relax in the expanding solar wind. Interestingly, measurements from Parker Solar Probe have shown the ubiquitous and persistent presence of the so-called switchbacks. These are magnetic field lines which are strongly perturbed to the point that they produce local inversions of the radial magnetic field. The corresponding signature of switchbacks in the velocity field is that of local enhancements in the radial speed (or jets) that display the typical velocity-magnetic field correlation that characterizes Alfv&amp;#233;n waves propagating away from the Sun.&amp;#160;While there is not yet a general consensus on what is the origin of switchbacks and their connection to coronal activity, a first necessary step to answer these important questions is to understand how they evolve and how long they can persist in the solar wind. Here we investigate the evolution of switchbacks. We address how their evolution is affected by parametric instabilities and the possible role of expansion, by comparing models with the observed radial evolution of the fluctuations&amp;#8217; amplitude. We finally discuss what are the implications of our results for models of switchback generation and related open questions.&lt;/p&gt;

Elevated Brain Iron in Cocaine Use Disorder as Indexed by Magnetic Field Correlation Imaging

2019 ◽  
Vol 4 (6) ◽  
pp. 579-588
Author(s):  
Vitria Adisetiyo ◽  
Corinne E. McGill ◽  
William H. DeVries ◽  
Jens H. Jensen ◽  
Colleen A. Hanlon ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Brain Iron ◽  
Cocaine Use ◽  
Field Correlation

scholarly journals Velocity-Magnetic Field Correlation of Pulsars

1996 ◽  
Vol 160 ◽  
pp. 49-50
Author(s):  
Naoki Itoh ◽  
Takemi Kotouda
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Field Model ◽  
Transverse Velocity ◽  
Distribution Model ◽  
Recent Measurement ◽  
Apparent Correlation ◽  
Magnetic Field Model ◽  
Field Correlation ◽  
The Magnetic Field

Monte Carlo simulations of the evolution of pulsars are carried out in order to compare with the recent measurement of the pulsar transverse velocity by Lyne &amp; Lorimer (1994). The new electron density distribution model of Taylor &amp; Cordes (1993) is adopted in the simulation. Accurate pulsar orbits in the Galactic gravitational field are calculated. It is found that the constant magnetic field model of pulsars can account for the new measurement of the pulsar transverse velocity and the apparent correlation between the strength of the magnetic field and the transverse velocity of the pulsars. The present finding confirms the validity of the constant magnetic field model of pulsars and consolidates the idea that the apparent correlation between the strength of the magnetic field and the transverse velocity of the pulsars is caused by observational selection effects.

Real-Space Quasilinear Theory of Drift Waves in a Sheared Magnetic Field

1977 ◽  
Vol 43 (2) ◽  
pp. 655-661 ◽  
Author(s):  
Tadatsugu Hatori ◽  
Y. C. Lee ◽  
Toshio Tange
Keyword(s):  
Magnetic Field ◽  
Real Space ◽  
Drift Waves ◽  
Quasilinear Theory

Reconstruction of the magnetic connection from Mercury to the solar corona

2020 ◽  
Author(s):  
Alessandro Ippolito ◽  
Christina Plainaki ◽  
Gaetano Zimbardo ◽  
Stefano Massetti ◽  
Anna Milillo
Keyword(s):  
Magnetic Field ◽  
Solar Corona ◽  
Magnetic Data ◽  
Monte Carlo Code ◽  
Correlation Lengths ◽  
Magnetic Fluctuation ◽  
Magnetic Field Model ◽  
Field Lines ◽  
Field Correlation ◽  
Accelerated Particles

&lt;p&gt;The magnetic foot point of Mercury on the solar disk has been reconstructed for selected case studies, in order to better understand the interaction between the solar corona and the planet. The transport of the magnetic field lines in the heliosphere is here evaluated with a Monte Carlo code that gives a random displacement at each step of the integration along the Parker magnetic field model. Such displacement is proportional to a &amp;#8220;local&amp;#8221; diffusion coefficient, which is a function of the fluctuation level and magnetic field correlation lengths. The simulation is tailored to specific events by using the observed values of solar wind velocity and magnetic fluctuation levels. Magnetic data from MAG/MESSENGER have been considered to compute the magnetic fluctuation level, while, concerning proton fluxes, FIPS/MESSENGER data has been taken into account. A number of SEP events observed on Mercury during 2011 and 2012 have been analysed, studying, for each event, the magnetic connection from Mercury to the solar corona, and the position of the active region possibly source of the accelerated particles observed.&lt;/p&gt;

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