Electrical determination of the spin relaxation time of photoexcited electrons in GaAs

Kurebayashi, Hidekazu; Trypiniotis, T.; Lee, K. Y.; Easton, S.; Ionescu, Adrian M.; Farrer, I.; Ritchie, D. A.; Bland, J. A. C.; Barnes, C. H. W.

doi:10.1063/1.3291066

Cited by 13 publications

(6 citation statements)

References 16 publications

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“…Quite a few studies of the electron spin transmission from a FM into a SC, and vice versa, have been carried out [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. In order to shed light on the transmission mechanism, in particular, from a SC into a FM, a tremendous approach using an optical spin orientation method was proposed by Prins et al [8], where spinpolarized photoelectrons are excited by the illumination of circular polarized light and the spin-dependent transmission across the interface was electrically detected: Circular polarized light can excite spin-polarized electrons efficiently in the SC according to the optical selection rules [11][12][13].…”

mentioning

confidence: 99%

Inversion of Spin Photocurrent due to Resonant Transmission

et al. 2010

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We report on the inversion of spin-dependent photocurrent via interface localized states formed at the interface of an Fe/n-AlGaAs/GaAs quantum well heterostructure by means of an optical spin orientation technique. A careful adjustment of the excitation photon energy, which is determined by a separate analysis of electroluminescence spectra under a spin injection condition, enables us to explore the spin-dependent characteristics of photoelectron transmission from the quantum well into Fe. The bias dependence of the spin-dependent photocurrent shows clear spikelike features at the voltage which is compatible with the formation of the interface localized resonant states in the Schottky depletion layer.

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confidence: 99%

Inversion of Spin Photocurrent due to Resonant Transmission

et al. 2010

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“…circularly polarised light creates spin-polarised electrons in GaAs via the optical selection rules [3] and an FM/SC interface is employed to measure the spin polarisation electrically. Despite a large number of investigations using this technique [4,5,6,7,8,9,10], there are no theoretical calculations supporting for them, to the authors' knowledge, except for recent tight-binding calculations on an Fe/GaAs interface by Honda et al [11]. Here, we present a phenomenological model designed for these photoexcitation experiments.…”

Section: Introductionmentioning

confidence: 93%

Numerical calculation model for spin-dependent transport of photoexcited electrons across Fe/GaAs(0 0 1) interfaces

Kurebayashi¹,

Trypiniotis²,

Lee³

et al. 2010

J. Phys. D: Appl. Phys.

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Abstract. Spin-dependent transport of photogenerated electrons across Fe/GaAs(001) interfaces is calculated using a one-dimensional electron transport model. Creation of spin-polarised electrons by photoexcitation in this model is defined by the band structure of GaAs along the [001] direction and the optical selection rules. The tunnel probability across the interface is obtained from Chang's model and first principles calculations are employed to calculate the spin polarisation of Fe for electrons propagating along the [001] direction. By combining the above ingredients, the spin filtering current, I SF , was calculated for different parameter values, including Schottky barrier height and photon energy. The model is used to fit with experimental results of the photoexcitation technique, yielding qualitative agreement especially for the observed sign switching of the spin filtering current.

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“…Since that fi rst experiment, there have been many related studies [16,[24][25][26][75][76][77][78][79][80][81][82][83][84][85][86]. Taniyama et al [78], Steinmuller et al [79] and Park et al [86] measured the spin-dependent photocurrent for Fe/AlO x /GaAs, NiFe(Fe)/GaAs and Fe/MgO/GaAs interfaces, respectively, under forward bias with optical spin orientation.…”

Section: Experimental Studies Of Spin Transport Into Ferromagnetsmentioning

confidence: 99%

“…As the spin polarization of electrons generated by optical spin orientation is strongly dependent on the energy of the circularly polarized light due to simultaneous excitations from the split-off subband at Γ 7 , tuning of the energy of light is critical to investigating the spin-dependent photocurrent across the interface. Kurebayashi et al [80] reported the inversion of sign in the spin-dependent photocurrent signal associated with the spin fi ltering eff ect upon varying the excitation energy. However, the values of spin-dependent photocurrent reported so far are at the few percent level, in clear contrast with the large spin polarization estimated from circular polarized electroluminescence as given in the previous section.…”

Section: Experimental Studies Of Spin Transport Into Ferromagnetsmentioning

confidence: 99%

Electrical and optical spin injection in ferromagnet/semiconductor heterostructures

et al. 2011

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T he operation of the rapidly expanding range of electronic devices, such as personal computers and mobile phones, is primarily based on the control of electron charge in semiconductors. Although the tremendous progress in microfabrication technologies has accelerated the miniaturization of electronic devices, the size of devices will soon encounter the fundamental physical limits of that miniaturization. Further scale reduction beyond these limits will require a radical alteration of the concept of functional devices. Control of the spin degree of freedom of an electron has brought about a new era of integration in electronics over the last ten years, and research in the fi eld of 'spintronics' is currently being pursued extensively due to the potential of this approach for the development of a new direction in electronics. Th e fi eld of spintronics spreads beyond the traditional boundaries among research fi elds, leading to interdisciplinary research that spans magnetism, semiconductors, photonics and electronics.Since 1990, a number of spin-based device concepts have been proposed. Spin-based transistors [1][2][3][4][5], spin light-emitting diodes (spin-LEDs) [6,7] and spin transfer torque memories [8,9] are typical examples. One of the device concepts is depicted in Figure 1, where the device structure consists of a ferromagnetic source electrode, a highmobility semiconductor channel, a ferromagnetic drain electrode and a gate electrode. To operate a spin-based functional device, the primary issue is the effi cient injection of spin-polarized electrons from the source ferromagnet into the semiconductor channel across the interface. Th e electron spin is then manipulated by the application of a voltage via the gate electrode [10], and the spin orientation is detected using a ferromagnetic drain electrode in a spin fi eld-eff ect transistor (FET) or from the circular polarization of light emission in a spin-LED. Although the device concept is very simple and similar to that of a conventional FET, the implementation of spin-based devices is not that straightforward: the spin degree of freedom must be handled very delicately because the spin current rapidly depolarizes at the ferromagnet/semiconductor interface and the spin information will be lost within a time scale of several hundred picoseconds, even in a semiconductor [11,12]. Th is is in clear contrast to the conservation of electron charge. Th erefore, there are still obstacles to overcome in the implementation of such spintronic devices, and for this purpose a clear understanding of not only electron spin transport processes from a ferromagnet into a semiconductor, and vice versa, but also electron spin dynamics in semiconductors, is of fundamental and technological importance.Our focus in this article is on reviewing the current status of this subject with special emphasis on electrical and optical spin injection Spin-based electronics or 'spintronics' is a rapidly expanding research area that off ers the promise of surpassing the limits of conventiona...

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Electrical determination of the spin relaxation time of photoexcited electrons in GaAs

Cited by 13 publications

References 16 publications

Inversion of Spin Photocurrent due to Resonant Transmission

Inversion of Spin Photocurrent due to Resonant Transmission

Numerical calculation model for spin-dependent transport of photoexcited electrons across Fe/GaAs(0 0 1) interfaces

Electrical and optical spin injection in ferromagnet/semiconductor heterostructures

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