Spin dynamics in semiconductors

Wu, M. W.; Jiang, J. H.; Weng, M. Q.

doi:10.48550/arxiv.1001.0606

Cited by 3 publications

(7 citation statements)

References 925 publications

(2,578 reference statements)

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“…It is already known that in a (001) 2D system with BIA and SIA we get an anisotropic spin-relaxation. [10][11][12] This has also been studied numerically in quasi-1D GaAs wires 13 . In this work, Sec.…”

Section: Introductionmentioning

confidence: 99%

Direction dependence of spin relaxation in confined two-dimensional systems

Wenk

Kettemann

2011

Phys. Rev. B

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The dependence of spin relaxation on the direction of the quantum wire under Rashba and Dresselhaus (linear and cubic) spin orbit coupling is studied. Comprising the dimensional reduction of the wire in the diffusive regime, the lowest spin relaxation and dephasing rates for (001) and (110) systems are found. The analysis of spin relaxation reduction is then extended to non-diffusive wires where it is shown that, in contrast to the theory of dimensional crossover from weak localization to weak antilocalization in diffusive wires, the relaxation due to cubic Dresselhaus spin orbit coupling is reduced and the linear part shifted with the number of transverse channels.

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Section: Introductionmentioning

confidence: 99%

Direction dependence of spin relaxation in confined two-dimensional systems

Wenk

Kettemann

2011

Phys. Rev. B

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“…25] with the increase of E from 0 to 0.05 kV/cm for the cases with T L ∼50-100 K but a slow increase of τ with the increase of E from 0 to 0.3 kV/cm for the case with T L = 300 K. (II) The heating of electrons by the electric field enhances the electron-phonon scattering and thus increases the spin relaxation time τ in the strong scattering limit. 4,[17][18][19][20][21] This effect, only important in the low temperature regime where the heating effect is strong [as shown in Fig. 2(c)], is responsible for the continuing increase of τ with E when E > 0.05 kV/cm and T L ∼50-100 K. To make the underlying physics depicted above more pronounced, a magnetic field B = 2 T is applied along the −x-direction for the cases with T L = 50 K and 300 K. The corresponding electric field dependences of τ are plotted as curves with open squares (T L = 50 K) and open circles (T L = 300 K) in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…This is caused by the enhanced inhomogeneous broadening of the effective magnetic field from the Dresselhaus spin-orbit coupling due to the drifting and heating of the electric field. 4,[17][18][19][20][21] This effect is easier to take place when the lattice temperature is high. 17,19 In Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The hot-electron spin relaxation/dephasing has been studied theoretically in both (001) quantum-well structures [17][18][19][20] and bulk materials, 21 by means of the kinetic spin Bloch equation (KSBE) approach. 4 The spin relaxation/dephasing time is found to increase with electric field when both the temperature and electric field are low, especially in high mobility samples. [17][18][19][20][21] When the electric field is high [for which the multi-subband (in confined nanostructures) 18 and/or multi-valley 19 effect have to be taken into account], the spin relaxation/dephasing time decreases with electric field.…”

Section: Introductionmentioning

confidence: 96%

“…Understanding spin relaxation is an important issue for the possible application of spintronic devices. [1][2][3][4] Among different kinds of spin relaxation mechanisms, [5][6][7] scattering plays an essential role. In general cases, phonons are assumed to form an equilibrium bath when carrierphonon scattering is considered.…”

Section: Introductionmentioning

confidence: 99%

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Effect of nonequilibrium phonons on hot-electron spin relaxation in n-type GaAs quantum wells

Zhang

2010

EPL

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We have studied the effect of nonequilibrium longitudinal optical phonons on hot-electron spin relaxation in n-type GaAs quantum wells. The longitudinal optical phonons, due to the finite relaxation rate, are driven to nonequilibrium states by electrons under an in-plane electric field. The nonequilibrium phonons then in turn influence the electron spin relaxation properties via modifying the electron heating and drifting. The spin relaxation time is elongated due to the enhanced electron heating and thus the electron-phonon scattering in the presence of nonequilibrium phonons. The frequency of spin precession, which is roughly proportional to the electron drift velocity, can be either increased (at low electric field and/or high lattice temperature) or decreased (at high electric field and/or low lattice temperature). The nonequilibrium phonon effect is more pronounced when the electron density is high and the impurity density is low.

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Spin relaxation due to random Rashba spin-orbit coupling in GaAs (110) quantum wells

Zhou¹,

Wu²

2010

Europhys. Lett.

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We investigate the spin relaxation due to the random Rashba spin-orbit coupling in symmetric GaAs (110) quantum wells from the fully microscopic kinetic spin Bloch equation approach. All relevant scatterings, such as the electron-impurity, electron-longitudinal-optical-phonon, electronacoustic-phonon, as well as electron-electron Coulomb scatterings are explicitly included. It is shown that our calculation reproduces the experimental data by Müller et al. [Phys. Rev. Lett. 101, 206601 (2008)] for a reasonable choice of parameter values. We also predict that the temperature dependence of spin relaxation time presents a peak in the case with low impurity density, which originates from the electron-electron Coulomb scattering.PACS numbers: 72.25. Rb, 71.70.Ej, 73.21.Fg Semiconductor spintronics has been an active field of research lately due to the potential application of spinbased devices.1-3 Recent experiments show that the spin relaxation time (SRT) in (110)-oriented GaAs quantum wells (QWs) is extremely long, and thus the spin dynamics in this system has attracted much attention both experimentally and theoretically.4-18 The physics underlying this effect is the absence of the D'yakonov-Perel' (DP) mechanism, 19 which is the leading spin relaxation mechanism in n-type zinc-blende semiconductors. The DP mechanism is from the joint effects of the momentum scattering and the momentum-dependent effective magnetic field (inhomogenous broadening 20 ) induced by the Dresselhaus 21 and the Rashba 22 spin-orbit coupling (SOC). In symmetric GaAs (110) QWs with only the lowest subband occupied, the in-plane component of the spin-orbit field vanishes.23 Therefore the DP mechanism cannot affect electrons with spin polarization along the growth direction and the SRT in this system is considerably larger than that in (100) QWs. In most of the previous works, the main reason limiting the SRT is attributed to the Bir-Aronov-Pikus mechanism, 24 which is from the exchange interaction between the electrons and the photo-generated holes. One of the exceptions is the spin noise spectroscopy measurement by Müller et al.,15 where the excitation of semiconductor is negligible and hence the Bir-Aronov-Pikus mechanism is avoided. They reported the longest SRT in this system which is about 24 ns. Since the DP and Bir-Aronov-Pikus mechanisms are both absent, and the virtual intersubband spin-flip SOC induced spin relaxation is also ruled out due to the relatively high mobility of the samples, 16 the possible reason limiting the SRT is the DP mechanism due to the random Rashba SOC caused by the fluctuations of the donor density. 25,26As shown by Sherman et al., 25,26 even in symmetric QWs, the unavoidable fluctuations of the concentration of the dopant ions still lead to a random electric field along the growth direction, and hence a random Rashba SOC at each point of a QW. This random SOC provides an inhomogeneous broadening and induces the DP spin relaxation. The previous investigations 25,26 on the spin relaxation due to this mechan...

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Spin dynamics in semiconductors

Cited by 3 publications

References 925 publications

Direction dependence of spin relaxation in confined two-dimensional systems

Direction dependence of spin relaxation in confined two-dimensional systems

Effect of nonequilibrium phonons on hot-electron spin relaxation in n-type GaAs quantum wells

Spin relaxation due to random Rashba spin-orbit coupling in GaAs (110) quantum wells

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