scholarly journals Irradiation-induced Kondo resonance in two-dimensional electron systems

2021 ◽  
Vol 2015 (1) ◽  
pp. 012056
Author(s):  
I. V. Iorsh ◽  
O. V. Kibis
Keyword(s):  
Quantum Wells ◽  
State Of The Art ◽  
Magnetic Moments ◽  
Resonant Scattering ◽  
Electron System ◽  
Kondo Temperature ◽  
Two Dimensional ◽  
Electron Systems ◽  
Kondo Resonance ◽  
Scattering States

Abstract We demonstrated theoretically that formation of the resonant scattering states in the two-dimensional (2D) electron system irradiated by a circularly polarized electromagnetic field leads to the emergence of localized magnetic moments. As a consequence, the corresponding Kondo resonances appear. For GaAs-based quantum wells and microwave fields, we estimate the Kondo temperature around 2.5 K, which can be detected in state-of-the-art measurements.

scholarly journals Quantum hall effects in two-dimensional electron systems: a global approach

2021 ◽  
Vol 137 (1) ◽  
Author(s):  
M. A. Hidalgo
Keyword(s):  
Quantum Wells ◽  
Hall Effect ◽  
Quantum Hall ◽  
Electron System ◽  
Two Dimensional ◽  
Electron Systems ◽  
Dimensional Electron ◽  
Hall Effects ◽  
Dimensional Electron System ◽  
Shubnikov De Haas Oscillations

AbstractUp to almost the last two decades all the experimental results concerning the quantum Hall effect (QHE), i.e. the observation of plateaux at integer or fractional (FQHE) values of the constant h/e2, were related to quantum-wells in semiconductor heterostructures. However, more recently, a renewed interest in revisiting these phenomena has arisen thanks to the observation of entirely similar effects in graphene and topological insulators. In this paper we show an approach encompassing all these QHEs using the same theoretical frame, entailing both Hall effect plateaux and Shubnikov-de Haas oscillations. Moreover, the model also enables the analysis of both phenomena as a function not only of the magnetic field but the gate voltage as well. More specifically, in the light of the approach, the FQHE in any two-dimensional electron system appears to be an effect of the breaking of the degeneration of every Landau level, n, as a result of the electrostatic interaction involved, and being characterized by the set of three integer numbers (n, p, q), where p and q have clear physical meanings too.

scholarly journals OSCILLATORY AND VANISHING RESISTANCE STATES IN MICROWAVE IRRADIATED 2D ELECTRON SYSTEMS

2004 ◽  
Vol 18 (27n29) ◽  
pp. 3465-3472 ◽  
Author(s):  
R. R. DU ◽  
M. A. ZUDOV ◽  
C. L. YANG ◽  
Z. Q. YUAN ◽  
L. N. PFEIFFER ◽  
...  
Keyword(s):  
High Frequency ◽  
High Mobility ◽  
Electron System ◽  
Two Dimensional ◽  
Electron Systems ◽  
Dimensional Electron ◽  
Dimensional Electron System ◽  
Zero Resistance ◽  
The Subject ◽  
Shubnikov De Haas Oscillations

Giant-amplitude oscillations in dc magnetoresistance of a high-mobility two-dimensional electron system can be induced by millimeterwave irradiations, leading to zero-resistance states at the oscillation minima. Following a brief overview of the now well-known phenomenon, this paper reports on aspects of more recent experiments on the subject. These are: new zero-resistance states associated with multi-photon processes; suppression of Shubnikov-de Haas oscillations by high-frequency microwaves; and microwave photoconductivity of a high-mobility two-dimensional hole system.

VANISHING HALL AND LONGITUDINAL RESISTANCES IN BILAYER TWO-DIMENSIONAL ELECTRON SYSTEMS AT νT=1

2004 ◽  
Vol 18 (27n29) ◽  
pp. 3677-3684
Author(s):  
MELINDA KELLOGG ◽  
JAMES P. EISENSTEIN ◽  
LOREN N. PFEIFFER ◽  
KENNETH W. WEST
Keyword(s):  
Filling Factor ◽  
Electron System ◽  
Two Dimensional ◽  
Electron Systems ◽  
Zero Temperature ◽  
Dimensional Electron ◽  
Superfluid State ◽  
Dimensional Electron System ◽  
Two Dimensional Electron Systems

Longitudinal and Hall resistances have been measured in a bilayer two-dimensional electron system at νT=1 with equal but oppositely directed currents flowing in the two layers. In the limit of zero temperature, both of these resistances are observed to drop to zero. This supports the prediction of an excitonic superfluid state existing at this total filling factor.

WEAK LOCALIZATION AND ITS APPLICATIONS AS AN EXPERIMENTAL TOOL

2010 ◽  
Vol 24 (12n13) ◽  
pp. 2015-2052 ◽  
Author(s):  
Gerd Bergmann
Keyword(s):  
Magnetic Moments ◽  
Weak Localization ◽  
Electron System ◽  
Spin Fluctuations ◽  
Magnetic Impurities ◽  
Electron Systems ◽  
Magnetic Systems ◽  
Disordered Films ◽  
Liquid Behavior ◽  
Important Field

The resistance of two-dimensional electron systems such as thin disordered films shows deviations from Boltzmann theory, which are caused by quantum corrections and are called weak localization. The theoretical origin of weak localization is the Langer–Neal graph in Kubo formalism. It represents an interference experiment with conduction electrons split into pairs of waves interfering in the back-scattering direction. The intensity of the interference (integrated over the time) can easily be measured by the resistance of the film. The application of a magnetic field B destroys the phase coherence after a time which is proportional to 1/B. For a field of 1 T this time is of the order of 1 ps. Therefore with a dc experiment, one can measure characteristic times of the electron system in the range of picoseconds. Weak localization has been applied to measure dephasing, spin-orbit scattering, tunneling times, etc. One important field of application is the investigation of magnetic systems and magnetic impurities by measuring the magnetic dephasing time and its temperature dependence. Here the Kondo maximum of spin-flip scattering, spin-fluctuations, Fermi liquid behavior and magnetic d-resonances have been investigated. Another field is the detection of magnetic moments for very dilute alloys and surface impurities. This article given a brief survey of different applications of weak localization with a focus on magnetic impurities.

Two-dimensional warm electron system in GaAs quantum wells at low temperatures

1990 ◽  
Vol 73 (1) ◽  
pp. 69-71 ◽  
Author(s):  
A. Kabasi ◽  
D. Chattopadhyay ◽  
P.C. Rakshit
Keyword(s):  
Quantum Wells ◽  
Low Temperatures ◽  
Electron System ◽  
Two Dimensional
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