PHOTOLUMINESCENCE OF IMPURITY-BOUND EXCITONS AND TRIONS IN MAGNETIC FIELDS

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1558-1562
Author(s):  
ARKADIUSZ WÓJS ◽  
LESZEK BRYJA ◽  
ANNA GŁADYSIEWICZ ◽  
JAN MISIEWICZ ◽  
MAREK POTEMSKI

Recombination spectrum of excitons and positive trions is studied by two-beam magneto-photoluminescence of a two-dimensional hole gas. For acceptor-bound trions a low-energy cyclotron replica is observed, corresponding to a hole shake-up process. The experiment is supplemented by realistic numerical calculations, allowing for identification of individual transitions and connecting the splitting of the shake-up line directly with the hole mass.

2011 ◽  
Vol 84 (13) ◽  
Author(s):  
Bin Xi ◽  
Shijie Hu ◽  
Jize Zhao ◽  
Gang Su ◽  
B. Normand ◽  
...  

2009 ◽  
Vol 23 (12n13) ◽  
pp. 2718-2722
Author(s):  
LESZEK BRYJA ◽  
ARKADIUSZ WÓJS ◽  
JAN MISIEWICZ ◽  
PAULINA PLOCHOCKA ◽  
MAREK POTEMSKI ◽  
...  

Positive trions in a quasi-two-dimensional hole gas confined in symmetric and asymmetric GaAs quantum wells are studied by a combination of polarization-resolved photoluminescence and transport measurements in high magnetic fields B (up to 23 T) and low temperatures (down to 30 mK). The experiments are accompanied by realistic numerical calculations. The whole family of trions (the singlet and a pair of triplets) are observed. The singlet-triplet crossing of Coulomb energies is found: hidden in symmetric and visible in asymmetric structures.


1999 ◽  
Vol 155 ◽  
pp. 95-151 ◽  
Author(s):  
Hideo Tamura

AbstractWe study the asymptotic behavior at low energy of scattering amplitudes in two dimensional magnetic fields with compact support. The obtained result depends on the total flux of magnetic fields. It should be noted that magnetic potentials do not necessarily fall off rapidly at infinity. The main body of argument is occupied by the resolvent analysis at low energy for magnetic Schrödinger operators with perturbations of lang-range class. We can show that the dimension of resonance spaces at zero energy does not exceed two. As a simple application, we also discuss the scattering by magnetic field with small support and the convergence to the scattering amplitude by δ-like magnetic field.


RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8654-8663
Author(s):  
Fatima Zahra Ramadan ◽  
Flaviano José dos Santos ◽  
Lalla Btissam Drissi ◽  
Samir Lounis

Based on density functional theory combined with low-energy models, we explore the magnetic properties of a hybrid atomic-thick two-dimensional (2D) material made of germanene doped with fluorine atoms in a half-fluorinated configuration (Ge2F).


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Yiming Chen ◽  
Victor Gorbenko ◽  
Juan Maldacena

Abstract We consider two dimensional CFT states that are produced by a gravitational path integral.As a first case, we consider a state produced by Euclidean AdS2 evolution followed by flat space evolution. We use the fine grained entropy formula to explore the nature of the state. We find that the naive hyperbolic space geometry leads to a paradox. This is solved if we include a geometry that connects the bra with the ket, a bra-ket wormhole. The semiclassical Lorentzian interpretation leads to CFT state entangled with an expanding and collapsing Friedmann cosmology.As a second case, we consider a state produced by Lorentzian dS2 evolution, again followed by flat space evolution. The most naive geometry also leads to a similar paradox. We explore several possible bra-ket wormholes. The most obvious one leads to a badly divergent temperature. The most promising one also leads to a divergent temperature but by making a projection onto low energy states we find that it has features that look similar to the previous Euclidean case. In particular, the maximum entropy of an interval in the future is set by the de Sitter entropy.


2015 ◽  
Vol 15 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Matthias Ratajczak ◽  
Thomas Wondrak ◽  
Klaus Timmel ◽  
Frank Stefani ◽  
Sven Eckert

AbstractIn continuous casting DC magnetic fields perpendicular to the wide faces of the mold are used to control the flow in the mold. Especially in this case, even a rough knowledge of the flow structure in the mold would be highly desirable. The contactless inductive flow tomography (CIFT) allows to reconstruct the dominating two-dimensional flow structure in a slab casting mold by applying one external magnetic field and by measuring the flow-induced magnetic fields outside the mold. For a physical model of a mold with a cross section of 140 mm×35 mm we present preliminary measurements of the flow field in the mold in the presence of a magnetic brake. In addition, we show first reconstructions of the flow field in a mold with the cross section of 400 mm×100 mm demonstrating the upward scalability of CIFT.


1993 ◽  
Vol 48 (8) ◽  
pp. 5095-5104 ◽  
Author(s):  
T. Komatsu ◽  
K. Koike ◽  
Y. Kaifu ◽  
S. Takeyama ◽  
K. Watanabe ◽  
...  

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