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

Acta Physica Sinica

Effect of carrier recombination on time-resolved Faraday rotation spectroscopy in GaAs quantum wells

Teng Li-Hua, Xia Wang

Published Jan 1, 2011• 0 citations
Publisher

Abstract

Based on the rate equations of a two-level system, time-resolved Faraday rotation spectroscopy model was developed. It was found that the carrier recombination has strong effect on the decay of Faraday rotation signal. The model was also used to fit the Faraday rotation spectra measured in GaAs quantum wells. The electron spin relaxation time was obtained as 73.5 ps. However, the spin relaxation time was obtained only as 51.3 ps with the single exponent to fit the Faraday rotation spectra. Thus, the conventional method with the single exponent to fit the Faraday rotation spectra is inaccurate.

DOI
10.7498/aps.60.057202

Related papers

Nearly degenerate time-resolved faraday rotation in quantum wells: The role of exciton-exciton interactions

Yu-Min Shen, Alexander Goebel, G. Khitrova +2 more

Experimental studies of nearly degenerate time-resolved Faraday rotation (TRFR) in GaAs and InGaAs quantum wells show that manybody interactions between excitons strongly modify the TRFR response from the electron spin coherence.

Conference on Lasers and Electro-Optics•Jan 1, 2006•0 citations

Spin dynamics of electrons and holes in InGaAs/GaAs quantum wells at millikelvin temperatures

L. V. Fokina, I. A. Yugova, Dmitri R. Yakovlev +6 more

The carrier spin dynamics in a $n$-doped (In,Ga)As/GaAs quantum well has been studied by time-resolved Faraday rotation and ellipticity techniques in the temperature range down to 430 milliKelvin. These techniques give data with very different spectral dependencies, from which nonetheless consistent information on the spin dynamics can be obtained, in agreement with theoretical predictions. The mechanisms of long-lived spin coherence generation are discussed for the cases of trion and exciton resonant excitation. We demonstrate that carrier localization leads to a saturation of spin relaxation times at 45 ns for electrons below 4.5 K and at 2 ns for holes below 2.3 K. The underlying spin relaxation mechanisms are discussed.

arXiv:1001.3228•Physical Review B•May 4, 2010•30 citations

Elliptically polarized pump-probe spectroscopy and its application to observation of electron-spin relaxation in GaAs quantum wells

Tianshu Lai, Luning Liu, Qian Shou +2 more

An elliptically polarized pump-probe spectroscopy is developed. A theoretical model is derived from the rate equations of two-level system with small signal approximation to describe the experimental signal of the spectroscopy. The spectroscopy eliminates the systematic errors between theories and experimental results in present circularly polarized pump-probe spectroscopy, and is implemented easily in experiments. The initial degree of spin polarization of carriers in an excited state can be extracted by means of the spectroscopy, which is an important parameter in the investigation of spatial transport of spin polarization. The electron-spin relaxation in GaAs quantum wells is studied by using this spectroscopy.

Applied Physics Letters•Nov 1, 2004•22 citations

Coherent spin dynamics of carriers in GaAs and CdTe semiconductor quantum wells

L. V. Fokina

Systematic investigation of the spin dephasing times in GaAs/(Al,Ga)As quantum wells and its depending on parameters like temperature, magnetic fields and doping will be shown in Chapter 3.In Chapter 4 are presented results of investigation of the nuclear spin systems in quantum well heterostructures.The chapter 5 presents the results of studying the carrier spin dynamics in a n-doped (In,Ga)As/GaAs quantum wells by time-resolved Faraday rotation and ellipticity techniques in the temperature range down to 430 mil-liKelvin.In Chapter 6 is devoted to experimental and theoretically studying of optical control of the spin coherence of quantum well electrons by short laser pulses with circular or linear polarization.For that purpose the coherent electron spin dynamics in a n-doped CdTe/(Cd,Mg)Te quantum well structure was measured by time-resolved pump-probe Kerr rotation, using resonant excitation of the negatively charged exciton (trion) state.on the eigenstates |s z ; ↑ and |s z ; ↓ yields the states themselves independent of time.Along the field axis (longitudinal direction) these quantum-mechanical spin states are thus stationary.Any loss of coherence is induced by coupling of those states with the environment.Applying the time-evolution operator on the spin states perpendicular

•Mar 24, 2010•0 citations

Spin Coherence of Holes in GaAs/AlGaAs Quantum Wells

M. Syperek, Dmitri R. Yakovlev, A. Greilich +4 more

Pump‐probe time‐resolved Kerr rotation technique has been used for experimental investigation of hole spin coherence in 15‐nm wide GaAs/AlGaAs quantum well structure in regime of diluted two‐dimensional hole gas. Due to the spectral width of 1.5 ps laser pulses which correspond to ∼1 meV, selective excitation of trion and exciton states has been performed. In the case of resonant excitation of exciton only the electron spin beats have been observed in the presence of magnetic field. In the case of resonant excitation of the positively charged exciton two component decay of time‐resolved Kerr rotation (TRKR) signal appeared. From the period of the quantum beat oscillation related to long decay component (up to 650 ps) of TRKR signal we obtained in‐plain hole g‐factor of ∼0.048±0.005.

AIP conference proceedings•Jan 1, 2007•5 citations

A new method for study of coherent exciton spin dynamics in GaAs quantum wells

Treena Grevatt, Nicholas Traynor, R.E. Worsley +1 more

Summary form only given. Ultrafast dephasing of excitons in semiconductor quantum wells is important because it presents insight into fundamental interactions and possible coherent control of optical properties. Standard measurement techniques include time- and frequency-domain four-wave mixing, resonant Rayleigh scattering, and Faraday rotation. We report on a new time-resolved technique based on reflective probing of pump-induced transient linear birefringence. This has various advantages, including sensitivity, applicability to opaque as-grown samples, ease of implementation, and freedom from superimposed signals.

Quantum Electronics and Laser Science Conference•Jun 7, 1996•0 citations
Based on the rate equations of a two-level system, time-resolved Faraday rotation spectroscopy model was developed. It was found that the carrier recombination has strong effect on the decay of Faraday rotation signal. The model was also used to fit the Faraday rotation spectra measured in GaAs quantum wells. The electron spin relaxation time was obtained as 73.5 ps. However, the spin relaxation time was obtained only as 51.3 ps with the single exponent to fit the Faraday rotation spectra. Thus, the conventional method with the single exponent to fit the Faraday rotation spectra is inaccurate.
The carrier spin dynamics in a nnn-doped (In,Ga)As/GaAs quantum well has been studied by time-resolved Faraday rotation and ellipticity techniques in the temperature range down to 430 milliKelvin. These techniques give data with very different spectral dependencies, from which nonetheless consistent information on the spin dynamics can be obtained, in agreement with theoretical predictions. The mechanisms of long-lived spin coherence generation are discussed for the cases of trion and exciton resonant excitation. We demonstrate that carrier localization leads to a saturation of spin relaxation times at 45 ns for electrons below 4.5 K and at 2 ns for holes below 2.3 K. The underlying spin relaxation mechanisms are discussed.
An elliptically polarized pump-probe spectroscopy is developed. A theoretical model is derived from the rate equations of two-level system with small signal approximation to describe the experimental signal of the spectroscopy. The spectroscopy eliminates the systematic errors between theories and experimental results in present circularly polarized pump-probe spectroscopy, and is implemented easily in experiments. The initial degree of spin polarization of carriers in an excited state can be extracted by means of the spectroscopy, which is an important parameter in the investigation of spatial transport of spin polarization. The electron-spin relaxation in GaAs quantum wells is studied by using this spectroscopy.
Systematic investigation of the spin dephasing times in GaAs/(Al,Ga)As quantum wells and its depending on parameters like temperature, magnetic fields and doping will be shown in Chapter 3.In Chapter 4 are presented results of investigation of the nuclear spin systems in quantum well heterostructures.The chapter 5 presents the results of studying the carrier spin dynamics in a n-doped (In,Ga)As/GaAs quantum wells by time-resolved Faraday rotation and ellipticity techniques in the temperature range down to 430 mil-liKelvin.In Chapter 6 is devoted to experimental and theoretically studying of optical control of the spin coherence of quantum well electrons by short laser pulses with circular or linear polarization.For that purpose the coherent electron spin dynamics in a n-doped CdTe/(Cd,Mg)Te quantum well structure was measured by time-resolved pump-probe Kerr rotation, using resonant excitation of the negatively charged exciton (trion) state.on the eigenstates |s z ; ↑ and |s z ; ↓ yields the states themselves independent of time.Along the field axis (longitudinal direction) these quantum-mechanical spin states are thus stationary.Any loss of coherence is induced by coupling of those states with the environment.Applying the time-evolution operator on the spin states perpendicular
Pump‐probe time‐resolved Kerr rotation technique has been used for experimental investigation of hole spin coherence in 15‐nm wide GaAs/AlGaAs quantum well structure in regime of diluted two‐dimensional hole gas. Due to the spectral width of 1.5 ps laser pulses which correspond to ∼1 meV, selective excitation of trion and exciton states has been performed. In the case of resonant excitation of exciton only the electron spin beats have been observed in the presence of magnetic field. In the case of resonant excitation of the positively charged exciton two component decay of time‐resolved Kerr rotation (TRKR) signal appeared. From the period of the quantum beat oscillation related to long decay component (up to 650 ps) of TRKR signal we obtained in‐plain hole g‐factor of ∼0.048±0.005.
Summary form only given. Ultrafast dephasing of excitons in semiconductor quantum wells is important because it presents insight into fundamental interactions and possible coherent control of optical properties. Standard measurement techniques include time- and frequency-domain four-wave mixing, resonant Rayleigh scattering, and Faraday rotation. We report on a new time-resolved technique based on reflective probing of pump-induced transient linear birefringence. This has various advantages, including sensitivity, applicability to opaque as-grown samples, ease of implementation, and freedom from superimposed signals.