scholarly journals Temperature-dependent linewidth of charged excitons in semiconductor quantum dots: Strongly broadened ground state transitions due to acoustic phonon scattering

2004 ◽  
Vol 69 (3) ◽  
Author(s):  
B. Urbaszek ◽  
E. J. McGhee ◽  
M. Krüger ◽  
R. J. Warburton ◽  
K. Karrai ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ground State ◽  
Acoustic Phonon ◽  
Phonon Scattering ◽  
Semiconductor Quantum Dots ◽  
State Transitions ◽  
Temperature Dependent

THE EFFECTS OF TEMPERATURE ON DIFFERENT LASER TRANSITIONS OF NEODYMIUM ORTHOVANADATE CRYSTAL

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Ganesan Krishnan ◽  
Noriah Bidin
Keyword(s):  
Laser Diode ◽  
Ground State ◽  
Phonon Scattering ◽  
Laser Crystal ◽  
Laser System ◽  
Temperature Dependent ◽  
Laser Transition ◽  
Level Laser ◽  
Effects Of Temperature ◽  
Terminal Level

The temperature dependence of Nd:YVO4 laser crystal pumped by laser diode emitting at 808 nm is studied within the range of 5 oC to 60 oC. The spectroscopy properties of quasi three level at 914 nm (4F3/2 - 4I 9/2) and four level at 1064 nm (4F3/2 - 4I 11/2) are characterized. The lineshape function of the transition lines were broadened as the temperature increases. The phenomenon is attributed to change in linewidth, lineshift and intensity. The linewidths for both laser transition of 914 nm and 1064 nm increases with temperature with the rate of 0.105 cm-1/oC and 0.074 cm-1/oC respectively. The peak of 914nm and 1064 nm lineshapes shifted to a longer wavelength with the rate of 3.0 pm/oC and 4.2 pm/oC respectively which correspond to same amount of lineshift. The lineshape broadening with respect to the temperature is due to one-phonon emission and Raman phonon scattering processes.  The intensities of 914 nm and 1064 nm transition lines are found to be decreased at the rate of 0.15 %/oC and 0.45 %/oC respectively due to non-radiative effects. Quasi three level laser transition is more temperature dependent because it terminal level is close to the ground state which suffers from higher phonon-ion interaction rather than four level laser system.

PHOTOLUMINESCENCE OF ULTRA SMALL InAs/GaAs QUANTUM DOTS

2005 ◽  
Vol 19 (18) ◽  
pp. 907-917 ◽  
Author(s):  
Y. G. LIN ◽  
C. H. WU ◽  
S. L. TYAN ◽  
S. D. LIN ◽  
C. P. LEE
Keyword(s):  
Quantum Dots ◽  
Phonon Scattering ◽  
Transition Energy ◽  
Tunneling Effect ◽  
Energy Separation ◽  
Hole State ◽  
Temperature Dependent ◽  
Pl Spectra ◽  
Shape Dependence ◽  
Electron And Hole States

The InAs/GaAs quantum dots (QDs) with a baselength of less than 10 nm are studied by the excitation-, temperature-dependent and magneto-photoluminescence (PL). The baselengths of the QDs, calculated by the PL ground state transition energy and estimated by magneto-PL spectra, are in agreement with the result of atomic force microscopy measurements. By means of the excitation-dependent PL, we demonstrate that only the ground electron and hole states exist when the baselength of the QDs is smaller than about 7.3 nm, whereas the larger dots with a baselength of about 8.7 nm will give rise to one excited hole state. The measured energy separation between the ground and the excited hole states is in good agreement with the theoretical calculation. The transition energy in temperature-dependent PL spectra shows a rapid redshift as the temperature is higher than the critical temperature. The redshift rate is about 2.8 and 2.5 times larger than the values calculated by Varshni's law for small and large dots respectively. The higher redshift rate can be explained by the stronger tunneling effect. In addition, the PL linewidths show a V-shape dependence with the temperature. This behavior could be well described as a tunneling and electron-phonon scattering effect.

scholarly journals Temperature dependence of ultrasharp luminescence lines in AlyIn1−yAs/AlxGa1−xAs self-assembled quantum dots

1996 ◽  
Vol 74 (S1) ◽  
pp. 216-219 ◽  
Author(s):  
S. Raymond ◽  
S. Fafard ◽  
S. Charbonneau
Keyword(s):  
Quantum Dots ◽  
Ground State ◽  
State Transition ◽  
Thermionic Emission ◽  
Excitation Density ◽  
High Excitation ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Self Assembled ◽  
Intensity Evolution

Ensembles of~600 AlyIn1−yAs/AlxGa1−xAs self-assembled quantum dots (QDs) are investigated using photoluminescence (PL) and time-resolved PL in the visible. At very low excitation intensities, the PL spectrum shows multiple ultranarrow luminescence lines (FWHM ~200 μeV), which are attributed to the ground-state transition of a few dots (4 or less). The temperature and intensity evolution of these sharp lines is then monitored. The temperature-dependent measurements show that the line width and lifetime of the narrow lines remain constant up to the onset of thermionic, emission. Intensity-dependent measurements show that for high excitation density the collective background, emitted by the ensemble of QDs, is enhanced relative to the amplitude of individual ultranarrow lines.

Effect of Pure Dephasing and Phonon Scattering on the Coupling of Semiconductor Quantum Dots to Optical Cavities

CLEO: 2015 ◽  
2015 ◽  
Author(s):  
Clément Jarlov ◽  
Etienne Wodey ◽  
Alexey Lyasota ◽  
Milan Calic ◽  
Pascal Gallo ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Phonon Scattering ◽  
Semiconductor Quantum Dots ◽  
Optical Cavities ◽  
Pure Dephasing

Theory of Addition Spectra in Double Quantum Dots: Single-Particle Tunneling vs Coulomb Interactions

1999 ◽  
Vol 571 ◽  
Author(s):  
M. Rontani ◽  
F. Rossi ◽  
F. Manghi ◽  
E. Molinari
Keyword(s):  
Quantum Dots ◽  
Ground State ◽  
Semiconductor Quantum Dots ◽  
Double Quantum ◽  
Coulomb Correlation ◽  
Coulomb Interactions ◽  
Double Quantum Dots ◽  
Quantum Transitions ◽  
New Phase ◽  
State Configuration

ABSTRACTWe study coupled semiconductor quantum dots theoretically using a generalized Hubbard approach, where intra- and inter-dot Coulomb correlation, as well as tunneling effects are described on the basis of realistic electron wavefunctions. We find that the ground-state configuration of vertically coupled double dots undergoes non-trivial quantum transitions as the inter-dot distance d changes; at intermediate values of d we predict a new phase that should be observable in the addition spectra and in the magnetization changes.

Temperature-dependent Rabi rotation in semiconductor quantum dots

2010 ◽  
Vol 96 (25) ◽  
pp. 251903
Author(s):  
K.-M. Hung ◽  
W.-J. Hong ◽  
K.-J. Su ◽  
T.-H. Shieh ◽  
K.-Y. Wu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Semiconductor Quantum Dots ◽  
Temperature Dependent
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