Spin beats and dynamical magnetization in quantum structures

Baumberg, Jeremy J.; Awschalom, D. D.; Samarth, N.; Luo, Hong‐Gang; Furdyna, J. K.

doi:10.1103/physrevlett.72.717

Cited by 137 publications

(76 citation statements)

References 8 publications

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“…[9][10][11][12][13] For such structures, however, the suppression of the DP mechanism occurs along one in-plane crystallographic orientation. While all-electrical devices are envisioned for most future semiconductor spintronics applications, optical spectroscopy techniques have proven to be very useful for the study of spin dynamics in direct-gap semiconductor heterostructures, and a variety of techniques, including time-resolved Faraday rotation (TRFR), 14 Hanle measurements, and spin noise spectroscopy (SNS) 15 have been developed. A number of experimental groups have studied spin dephasing in various (110)-grown systems.…”

Section: Introductionmentioning

confidence: 99%

Strongly anisotropic spin relaxation revealed by resonant spin amplification in (110) GaAs quantum wells

et al. 2012

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We have studied spin dephasing in a high-mobility two-dimensional electron system confined in a GaAs/AlGaAs quantum well grown in the [110] direction, using the resonant spin amplification (RSA) technique. From the characteristic shape of the RSA spectra, we are able to extract the spin dephasing times (SDTs) for electron spins aligned along the growth direction or within the sample plane, as well as the g factor. We observe a strong anisotropy in the spin dephasing times. While the in-plane SDT remains almost constant as the temperature is varied between 4 and 50 K, the out-of-plane SDT shows a dramatic increase at a temperature of about 25 K and reaches values of about 100 ns. The SDTs at 4 K can be further increased by additional, weak above-barrier illumination. The origin of this unexpected behavior is discussed. The SDT enhancement is attributed to the redistribution of charge carriers between the electron gas and remote donors.

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Section: Introductionmentioning

confidence: 99%

Strongly anisotropic spin relaxation revealed by resonant spin amplification in (110) GaAs quantum wells

et al. 2012

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“…This gives rise to coupling with another spin system of different spin relaxation times which can influence the exciton spins [31].…”

Section: Future Directionsmentioning

confidence: 99%

Optical Processes in Quantum Wells

Sham

1995

Acta Phys. Pol. A

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A review is given of the theoretical framework of exciton dynamics in quantum wells including the spin degrees of freedom. A study is made of various momentum, energy, and spin relaxation mechanisms including the effects of exciton-phonon interaction, the single-particle spin-flips by means of spin-orbit interaction and the exciton spin-ffip by means of the exchange interaction. All these competing mechanisms are taken into account in a set of equations governing the time evolution of the exciton spin populations. Solutions are then used to interpret observed time-resolved observations of polarized luminescence spectra. For excitons in a two-dimensional system such as a semiconductor quantum well, the breaking of the translational symmetry in the direction normal to the interface plane has been shown theoretically by Hanamura, by Andreani and Bassani, and by Citrin to result in a reckbination rate much faster than in a three-dimensional system. Yet, experiments show ckparable decay rates in two-and three-dimensional excitons. Recent experiments with high time resolutions show two decay times for the total luminescence intensity. The slower one agrees witl the one usually observed and interpreted as the radiative recombination time. We shall give an explanation for the fast decay as a ckbination of radiative recombination and single-particle spin-flip and for the slow decay as the radiative recombination slowed down by the presence of lower energy dark states for excitons with parallel spins. The ability to use the same theory to account for the polarization behavior confirms the importance of the exciton spin dynamics. Furthermore, the longitudinal electric field dependence is used to check our theory of exchange.

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“…Later, the photoinduced spin alignment was precisely observed from time-resolved Faraday rotation, where a small variation in the Mn spin momentum was captured after photoexcitation. [6][7][8] Moreover, a large photoinduced magnetization has recently been demonstrated in ferromagnetic DMSs based on a III-V material. 9) To design high-yield and fast-response spintronic devices, a clear understanding of the photocarrier relaxation is obviously required.…”

Section: Introductionmentioning

confidence: 99%

Spin-Flip Energy Transfer from Photocarriers to Magnetic Ions in (Cd,Mn)Te

et al. 2006

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The process of energy exchange from photoinjected carriers to magnetic ions is studied by means of polarization-dependent magnetophotoluminescence in Cd 1Àx Mn x Te (x Mn ¼ 0:1). It is observed for the first time that the photothermalization of magnetic ions depends on the initial spin state of carriers, prepared by circularly polarized excitation, revealing the contribution of the spin flip-flop process to the energy transfer. Suppression of heat accumulation, exploiting low-repetition pulsed excitation, enables us to temporally resolve the spin exchange process associated with a single scattering event. Our results suggest the presence of spatial distribution in magnetization as a result of rapid carrier localization.

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Spin beats and dynamical magnetization in quantum structures

Cited by 137 publications

References 8 publications

Strongly anisotropic spin relaxation revealed by resonant spin amplification in (110) GaAs quantum wells

Strongly anisotropic spin relaxation revealed by resonant spin amplification in (110) GaAs quantum wells

Optical Processes in Quantum Wells

Spin-Flip Energy Transfer from Photocarriers to Magnetic Ions in (Cd,Mn)Te

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