scholarly journals Localization-delocalization transition in disordered one-dimensional exciton-polariton system

2018 ◽  
Vol 52 (4) ◽  
pp. 468
Author(s):  
A.V. Larionov ◽  
A.S. Brichkin ◽  
S. Hofling ◽  
V.D. Kulakovskii
Keyword(s):  
Critical Level ◽  
Localization Length ◽  
Blue Shift ◽  
High Energy ◽  
One Dimensional ◽  
Glass State ◽  
Localized State ◽  
Bose Glass ◽  
The Wire ◽  
Excitation Spot

AbstractThe transition from the delocalized to the localized state has been investigated in a quasi-onedimensional exciton-polariton system excited nonresonantly in GaAs-based microcavity wire with disordered potential. The photoexcited polariton condensate has been found to spread along the wire with а velocity exceeding 1 μm/ps. The propagation along the wire is provided by high energy polaritons. The LP localization length decreases with decreasing blue shift of LPs in the excited spot. The polariton condensate returns to the Bose glass state when the blue shift of the LP resonance at the excitation spot decreases below the critical level that depends on the potential disorder.

scholarly journals Phonon Localization in Boron Nitride Nanotubes: Mixing Effect of 10B Isotopes and Vacancies

2021 ◽  
Author(s):  
Md. Sherajul Islam ◽  
Ashraful Hossain Howlader ◽  
Rongkun Zheng ◽  
Catherine Stampfl ◽  
Jeongwon Park ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Localization Length ◽  
Low Frequency ◽  
Blue Shift ◽  
High Energy ◽  
Boron Nitride Nanotubes ◽  
Forced Oscillation Technique ◽  
Phonon Modes ◽  
Mixing Effect ◽  
Phonon Localization

Abstract We explored the mixing effect of 10B isotopes and boron (B) or nitrogen (N) vacancies on the atomic vibrational properties of (10, 0) single-wall boron nitride nanotubes (BNNT). The forced oscillation technique was employed to evaluate the phonon modes for the entire range (0-100%) of 10B isotopes and atomic vacancy densities ranging from 0 to 30%. With increasing isotope densities, we noticed a blue-shift of the Raman active A1 phonon peak, whereas an increased density of mixed or independent B and N vacancies resulted in the emergence of a new low-frequency peak and the annihilation of the A1 peak in the phonon density-of-states. High-energy optical phonons were localized as a result of both 10B isotopes and the presence of mixing defects. We generated typical mode patterns for different defects to show the phonon localization processes due to the defects. We found an asymmetrical nature of the localization length with increasing 10B isotope content, which corresponds well with the isotope inherited localization length of carbon nanotubes and mono-layer graphene. The localization length falls abruptly with the increase in concentration of both atomic vacancies (B or N) and mixing defects (10B isotope and vacancies). These findings are critical for understanding heat conduction and nanoscopic vibrational investigations like tip-enhanced Raman spectra in BNNT, which can map local phonon energies.

Bose-glass state in one-dimensional random antiferromagnets

2009 ◽  
Vol 79 (9) ◽  
Author(s):  
Hirotaka Manaka ◽  
Hiroko Aruga Katori ◽  
Oleksandr Viktorovych Kolomiets ◽  
Tuneaki Goto
Keyword(s):  
One Dimensional ◽  
Glass State ◽  
Bose Glass

Origin of Blue Shifts in Quantum-Well Wires Unrelated to Lateral Confinement

1992 ◽  
Vol 283 ◽  
Author(s):  
Anders Gustafsson ◽  
X. Liu ◽  
I. Maximov ◽  
L. Samuelson ◽  
W. Seifert
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Blue Shift ◽  
High Energy ◽  
Peak Position ◽  
Lateral Confinement ◽  
Quantum Well Wire ◽  
Quantum Well Wires ◽  
The Wire ◽  
Spectrally Resolved

ABSTRACTExperimentally observed blue shifts of the peak position of the luminescence from quantum-well-wire and -dot structures are often significantly larger than the calculated shifts induced by lateral confinement in the structures. In this work we have used high-quality InGaAsAnP multi-quantum-wells for the fabrication of wires. The quantum wells are in the range 3 to 17 monolayers (ML) nominally. The thinnest well, 3 ML, shows a clearly resolved split into two luminescence peaks from areas with a thickness difference of 1 ML. In the case of the wires, the luminescence from the thicker wells show a blue shift, as well a significant broadening. However, the thinnest well shows no blue shift, but a different ratio of the two peaks, with the high energy peak favoured in the wire case. We interpret these effects in terms of a reduced transfer of excitons from thinner to thicker areas of the well in the wire as compared to the unpattemed areas. This due to a reduction of the transfer from 2 dimensional to 1 dimensional in the wires. The peaks originating in areas of different ML thicknesses are not spectrally resolved in the thicker wells and the reduced transfer therefore results in a blue shift as well as a broadening of the luminescence peak.

scholarly journals Effects of Accumulated Energy on Nanoparticle Formation in Pulsed-Laser Dewetting of AgCu Thin Films

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
H. K. Lin ◽  
C. W. Huang ◽  
Y. H. Lin ◽  
W. S. Chuang ◽  
J. C. Huang
Keyword(s):  
Pulsed Laser ◽  
Blue Shift ◽  
High Energy ◽  
Low Energy ◽  
Nanoparticle Formation ◽  
Energy Accumulation ◽  
Glass Substrates ◽  
Peak Absorption ◽  
Two Peaks ◽  
Sputtering System

AbstractAg50Cu50 films were deposited on glass substrates by a sputtering system. Effects of accumulated energy on nanoparticle formation in pulse-laser dewetting of AgCu films were investigated. The results showed that the properties of the dewetted films were found to be dependent on the magnitude of the energy accumulated in the film. For a low energy accumulation, the two distinct nanoparticles had rice-shaped/Ag60Cu40 and hemispherical/Ag80Cu20. Moreover, the absorption spectra contained two peaks at 700 nm and 500 nm, respectively. By contrast, for a high energy accumulation, the nanoparticles had a consistent composition of Ag60Cu40, a mean diameter of 100 nm and a peak absorption wavelength of 550 nm. Overall, the results suggest that a higher Ag content of the induced nanoparticles causes a blue shift of the absorption spectrum, while a smaller particle size induces a red shift.

scholarly journals LOCALIZED ENTANGLEMENT IN ONE-DIMENSIONAL ANDERSON MODEL

2005 ◽  
Vol 19 (11) ◽  
pp. 517-527 ◽  
Author(s):  
HAIBIN LI ◽  
XIAOGUANG WANG
Keyword(s):  
Anderson Model ◽  
Localization Length ◽  
Direct Relation ◽  
Disorder Strength ◽  
One Dimensional ◽  
Entanglement Distribution ◽  
Localization Center

The entanglement in one-dimensional Anderson model is studied. The pairwise entanglement has a direct relation to the localization length and is reduced by disorder. Entanglement distribution displays the entanglement localization. The pairwise entanglements around localization center exhibit a maximum as the disorder strength increases. The dynamics of entanglement are also investigated.

scholarly journals Absence of high-energy spectral concentration for Dirac systems with divergent potentials

2005 ◽  
Vol 135 (4) ◽  
pp. 689-702 ◽  
Author(s):  
M. S. P. Eastham ◽  
K. M. Schmidt
Keyword(s):  
Spectral Density ◽  
High Energy ◽  
Regularity Conditions ◽  
Absolutely Continuous Spectrum ◽  
Absolutely Continuous ◽  
One Dimensional ◽  
Local Maxima ◽  
Dirac Systems ◽  
Additional Regularity ◽  
Spectral Concentration

It is known that one-dimensional Dirac systems with potentials q which tend to −∞ (or ∞) at infinity, such that 1/q is of bounded variation, have a purely absolutely continuous spectrum covering the whole real line. We show that, for the system on a half-line, there are no local maxima of the spectral density (points of spectral concentration) above some value of the spectral parameter if q satisfies certain additional regularity conditions. These conditions admit thrice-differentiable potentials of power or exponential growth. The eventual sign of the derivative of the spectral density depends on the boundary condition imposed at the regular end-point.

High-Energy-Density Polymer Nanocomposites Composed of Newly Structured One-Dimensional BaTiO3@Al2O3 Nanofibers

2017 ◽  
Vol 9 (4) ◽  
pp. 4024-4033 ◽  
Author(s):  
Zhongbin Pan ◽  
Lingmin Yao ◽  
Jiwei Zhai ◽  
Dezhou Fu ◽  
Bo Shen ◽  
...  
Keyword(s):  
Energy Density ◽  
Polymer Nanocomposites ◽  
High Energy ◽  
High Energy Density ◽  
One Dimensional

scholarly journals Nonlinear Optical Rectification of Tuned Quantum Dots Under the Action of a Vertical Magnetic Field

2021 ◽  
Author(s):  
Zhuang Zhao
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Nonlinear Optical ◽  
Blue Shift ◽  
High Energy ◽  
Optical Rectification ◽  
Mass Approximation ◽  
Structure Plane ◽  
Nonlinear Optical Rectification ◽  
Peak Value

Abstract The effects of tuned quantum dots (QD) on the optical rectification (OR) coefficient under the action of the external magnetic field, hydrostatic pressure, temperature and quantum dot radius is theoretically studied in detail. The tuned quantum dots are subjected to a uniform magnetic field perpendicular to the structure plane. Within the framework of effective mass approximation and parabolic approximation, the energy level and wave function are derived, and the nonlinear optical rectification coefficients are calculated by the compact density matrix method and iterative method. Numerical results show that under different constraint parameters, the resonance peak of the OR coefficient moves in the direction of high energy or low energy, that is, red shift or blue shift. At the same time, the peak value of the OR coefficient will increase or decrease with the change of the parameters.

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