Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Applied Physics Letters

Radiatively limited dephasing of quantum dot excitons in the telecommunications wavelength range

Junko Ishi‐Hayase, Kouichi Akahane, Naokatsu Yamamoto, Masahide Sasaki, Mamiko Kujiraoka, Kazuhiro Ema

Published Sep 3, 2007• 17 citations
Publisher

Abstract

The extremely long dephasing time of excitons in strain-compensated quantum dots at telecommunications wavelengths was measured using a polarization-dependent four-wave mixing technique. The use of a 150-layer-stacked structure enabled them to measure a four-wave mixing signal with a high signal-to-noise ratio, in spite of the fact that a high-sensitive heterodyne detection was not used. The large anisotropy of the dephasing time indicates the dominance of the radiative recombination process on dephasing. By simultaneously measuring the radiative lifetime using a pump-probe technique, they could directly estimate pure dephasing with an accuracy of better than 0.1μeV.

DOI
10.1063/1.2780120

Related papers

Exciton dephasing in strain-compensated self-assembled InAs quantum dots

Junko Ishi‐Hayase, Kouichi Akahane, Naokatsu Yamamoto +3 more

We investigate the dephasing of excitons in InAs self-assembled quantum dots by using a transient four-wave-mixing technique. A used sample is specially designed to compensate the strain. We observe long-lived coherence of excitons at 5 K which corresponds to the dephasing time longer than a nanosecond, where the photon energy of the excitation pulse is 0.874~eV. We find that a pure dephasing due to exciton-phonon interactions dominates in the exciton dephasing rather than the population decay and the exciton-exciton interaction in the weak excitation region, by analyzing the population lifetime and the polarization-dependent dephasing time.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 9, 2006•1 citation

Radiatively limited dephasing in InAs quantum dots

W. Langbein, Paola Borri, U. Woggon +3 more

We measure the dephasing time of the exciton ground-state transition in ${\mathrm{In}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}\mathrm{As}$ quantum dots using a sensitive four-wave mixing technique. We find experimental evidence that the dephasing time is given only by the radiative lifetime at low temperatures. We demonstrate the tunability of the radiatively limited dephasing time from $400\phantom{\rule{0.3em}{0ex}}\mathrm{ps}$ up to $2\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$ in a series of annealed ${\mathrm{In}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}\mathrm{As}$ quantum dots with increasing quantum-confinement energy from $69\phantom{\rule{0.3em}{0ex}}\mathrm{meV}\phantom{\rule{0.5em}{0ex}}\text{to}\phantom{\rule{0.5em}{0ex}}330\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$.

Physical Review B•Jul 1, 2004•202 citations

Polarization-Dependent Four-Wave Mixing Measurements in Highly-stacked InAs Quantum Dots

Mamiko Kujiraoka, Junko Ishi‐Hayase, Kouichi Akahane +3 more

We measure the polarization dependence of four‐wave mixing (FWM) signals in highly‐stacked InAs quantum dots on an InP(311)B substrate. Dephasing time T2 and FWM signal intensity show large anisotropy for the crystal axes. The measured T2 is determined only by the exciton population lifetime, and thus the polarization dependence of T2 reflects the difference of the transition dipole moments related to bright exciton states with orthogonally linear polarizations.

AIP conference proceedings•Jan 1, 2007•3 citations

Ultralong Dephasing Time in InGaAs Quantum Dots

Paola Borri, W. Langbein, Stephan Schneider +4 more

We measure a dephasing time of several hundred picoseconds at low temperature in the ground-state transition of strongly confined InGaAs quantum dots, using a highly sensitive four-wave mixing technique. Between 7 and 100 K the polarization decay has two distinct components resulting in a non-Lorentzian line shape with a lifetime-limited zero-phonon line and a broadband from elastic exciton-acoustic phonon interactions.

Physical Review Letters•Sep 1, 2001•996 citations

Exciton relaxation and dephasing in quantum-dot amplifiers from room to cryogenic temperature

Paola Borri, W. Langbein, Stephan Schneider +4 more

We present an extensive experimental study of the exciton relaxation and dephasing in InGaAs quantum dots (QDs) in the temperature range from 10 K to 295 K. The QDs are embedded in the active region of an electrically pumped semiconductor optical amplifier. Ultrafast four-wave mixing and differential transmission spectroscopy on the dot ground-state transition are performed with a sensitive heterodyne detection technique. The importance of the population relaxation dynamics to the dephasing is determined as a function of injection current and temperature. Above 150 K dephasing processes much faster than the population relaxation are present, due to both carrier-phonon scattering and Coulomb interaction with the injected carriers. Only at low temperatures (<30 K) does population relaxation of multiexcitons in the gain regime fully determine the dephasing.

IEEE Journal of Selected Topics in Quantum Electronics•Sep 1, 2002•102 citations

Temperature dependence homogeneous broadening and gain recovery dynamics in InGaAs quantum dots

Paola Borri, W. Langbein, Stephan Schneider +4 more

We present temperature-dependent measurements of the dephasing time in the ground-state transition of strongly-confined InGaAs quantum dots, using a highly sensitive four-wave mixing technique. At low temperature we measure a dephasing time of several hundred picoseconds. Between 7 and 100 K the polarization decay has two distinct components resulting in a non-Lorentzian lineshape with a sharp zero-phonon line and a broad band from elastic exciton-acoustic phonon interactions. We also explore the dephasing time beyond the one exciton occupation, by electrically injecting carriers. Electrical injection into the barrier region results in a dominantly pure dephasing of the excitonic ground-state transition. Once the injected carriers have filled the electronic ground state, additional filling of the excited states creates multiexcitons that show a fast dephasing due to population relaxation.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jun 5, 2002•0 citations
The extremely long dephasing time of excitons in strain-compensated quantum dots at telecommunications wavelengths was measured using a polarization-dependent four-wave mixing technique. The use of a 150-layer-stacked structure enabled them to measure a four-wave mixing signal with a high signal-to-noise ratio, in spite of the fact that a high-sensitive heterodyne detection was not used. The large anisotropy of the dephasing time indicates the dominance of the radiative recombination process on dephasing. By simultaneously measuring the radiative lifetime using a pump-probe technique, they could directly estimate pure dephasing with an accuracy of better than 0.1μeV.
We investigate the dephasing of excitons in InAs self-assembled quantum dots by using a transient four-wave-mixing technique. A used sample is specially designed to compensate the strain. We observe long-lived coherence of excitons at 5 K which corresponds to the dephasing time longer than a nanosecond, where the photon energy of the excitation pulse is 0.874~eV. We find that a pure dephasing due to exciton-phonon interactions dominates in the exciton dephasing rather than the population decay and the exciton-exciton interaction in the weak excitation region, by analyzing the population lifetime and the polarization-dependent dephasing time.
We measure the dephasing time of the exciton ground-state transition in ${\mathrm{In}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}\mathrm{As}$ quantum dots using a sensitive four-wave mixing technique. We find experimental evidence that the dephasing time is given only by the radiative lifetime at low temperatures. We demonstrate the tunability of the radiatively limited dephasing time from 400ps400\phantom{\rule{0.3em}{0ex}}\mathrm{ps}400ps up to 2ns2\phantom{\rule{0.3em}{0ex}}\mathrm{ns}2ns in a series of annealed ${\mathrm{In}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}\mathrm{As}$ quantum dots with increasing quantum-confinement energy from 69meVto330meV69\phantom{\rule{0.3em}{0ex}}\mathrm{meV}\phantom{\rule{0.5em}{0ex}}\text{to}\phantom{\rule{0.5em}{0ex}}330\phantom{\rule{0.3em}{0ex}}\mathrm{meV}69meVto330meV.
We present an extensive experimental study of the exciton relaxation and dephasing in InGaAs quantum dots (QDs) in the temperature range from 10 K to 295 K. The QDs are embedded in the active region of an electrically pumped semiconductor optical amplifier. Ultrafast four-wave mixing and differential transmission spectroscopy on the dot ground-state transition are performed with a sensitive heterodyne detection technique. The importance of the population relaxation dynamics to the dephasing is determined as a function of injection current and temperature. Above 150 K dephasing processes much faster than the population relaxation are present, due to both carrier-phonon scattering and Coulomb interaction with the injected carriers. Only at low temperatures (<30 K) does population relaxation of multiexcitons in the gain regime fully determine the dephasing.
We present temperature-dependent measurements of the dephasing time in the ground-state transition of strongly-confined InGaAs quantum dots, using a highly sensitive four-wave mixing technique. At low temperature we measure a dephasing time of several hundred picoseconds. Between 7 and 100 K the polarization decay has two distinct components resulting in a non-Lorentzian lineshape with a sharp zero-phonon line and a broad band from elastic exciton-acoustic phonon interactions. We also explore the dephasing time beyond the one exciton occupation, by electrically injecting carriers. Electrical injection into the barrier region results in a dominantly pure dephasing of the excitonic ground-state transition. Once the injected carriers have filled the electronic ground state, additional filling of the excited states creates multiexcitons that show a fast dephasing due to population relaxation.