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

Physical Review B

Radiatively limited dephasing in InAs quantum dots

W. Langbein, Paola Borri, U. Woggon, V. Stavarache, D. Reuter, Andreas Dirk Wieck

Published Jul 1, 2004• 202 citations
Publisher

Abstract

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 $69\phantom{\rule{0.3em}{0ex}}\mathrm{meV}\phantom{\rule{0.5em}{0ex}}\text{to}\phantom{\rule{0.5em}{0ex}}330\phantom{\rule{0.3em}{0ex}}\mathrm{meV}$.

DOI
10.1103/physrevb.70.033301

Related papers

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

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

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

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.

Applied Physics Letters•Sep 3, 2007•17 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

Coherence and dephasing in self-assembled quantum dots

J. M. Hvam, Kristján Leósson, D. Birkedal

We measured dephasing times in InGaAlAs self-assembled quantum dots at low temperature using degenerate four-wave mixing. At 0 K, the coherence time of the quantum dots is lifetime limited, whereas at finite temperatures pure dephasing by exciton-phonon interactions governs the quantum dot coherence. The inferred homogeneous line widths are significantly smaller than the line widths usually observed in the photoluminescence from single quantum dots indicating an additional inhomogeneous broadening mechanism in the latter.

IEEE Conference on Nanotechnology (IEEE NANO)•Jan 23, 2004•0 citations

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

Temperature-Dependent Time-Resolved Four-Wave Mixing in InGaAs Quantum Dots

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

Time-resolved four-wave mixing in strongly confined and electrically pumped InGaAs quantum dots is measured at different temperatures. Without electrical injection, the dephasing time of the dot ground state transition is lifetime-limited and of several hundred picoseconds at low temperature. Under electrical injection, the sum of the contributions from empty and populated dots with a relative phase shift of π is evidenced near transparency.

physica status solidi (a)•Apr 1, 2002•1 citation
We measure the dephasing time of the exciton ground-state transition in In1\ensuremath−xGaxAs{\mathrm{In}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}\mathrm{As}In1\ensuremath−x​Gax​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 In1\ensuremath−xGaxAs{\mathrm{In}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}\mathrm{As}In1\ensuremath−x​Gax​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.
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 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.
We measured dephasing times in InGaAlAs self-assembled quantum dots at low temperature using degenerate four-wave mixing. At 0 K, the coherence time of the quantum dots is lifetime limited, whereas at finite temperatures pure dephasing by exciton-phonon interactions governs the quantum dot coherence. The inferred homogeneous line widths are significantly smaller than the line widths usually observed in the photoluminescence from single quantum dots indicating an additional inhomogeneous broadening mechanism in the latter.
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.