Gas Laser in a Magnetic Field

Abstract:We study both theoretically and experimental1 the luminescence in non-intentionally but heavily p-doped GaAs quantum wells of 55 and 1501 width. At T=2K the PL spectra under cw excitation present an excitonic peak and a broad acceptor band. Time-resolved optical pumping of the acceptor line allows us to measure the free electron spin relaxation time. We have investigated its temperature dependence in the 4-40K range. The experimental findings are interpreted in the framework of the D'Yakonov-Perel' mechanism for the electron gas.

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“…The last one dominates and gives for the spin-flip probability l/Tsf oc ~1 2 (see ref. [5] where El is the energy of A.…”

Section: Theoretical Considerationsmentioning

confidence: 99%

Electron spin-polarization in p-doped quantum wells

Ferreira¹,

Roussignol²,

Rolland³

et al. 1993

Le Journal de Physique IV

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“…However, in all III-V semiconductor materials spin ensembles rapidly dephase due to the D'yakonov-Perel' (DP) spin-dephasing mechanism [3][4][5]. For the case of electron ensembles in a heterojunction two-dimensional electron gas (2DEG), two distinct contributions to DP spin-dephasing have to be considered: the inversion asymmetry of the confining potential (structural inversion asymmetry) and the bulk inversion J. Liu · T. Last ( ) · E.J.…”

Section: Introductionmentioning

confidence: 99%

Spin-Dephasing Anisotropy for Electrons in a Diffusive Quasi-1D GaAs Wire

Liu

Last

Koop

et al. 2009

J Supercond Nov Magn

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We present a numerical study of dephasing of electron spin ensembles in a diffusive quasi-one-dimensional GaAs wire due to the D'yakonov-Perel' spin-dephasing mechanism. For widths of the wire below the spin precession length and for equal strength of Rashba and linear Dresselhaus spin-orbit fields a strong suppression of spin-dephasing is found. This suppression of spin-dephasing shows a strong dependence on the wire orientation with respect to the crystal lattice. The relevance for realistic cases is evaluated by studying how this effect degrades for deviating strength of Rashba and linear Dresselhaus fields, and with the inclusion of the cubic Dresselhaus term.

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“…is anisotropic [20]. Experimental verification of the existence of Dyakonov waves came only in 2009, when Takayama et al were able to excite a Dyakonov wave guided by the interface of a liquid and a biaxial dielectric crystal [21].…”

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confidence: 99%

Observation of the Dyakonov-Tamm Wave

2013

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Abstract.A surface electromagnetic wave called the Dyakonov-Tamm wave has been theoretically predicted to exist at the interface of two dielectric materials at least one of which is both anisotropic and periodically nonhomogeneous. For experimental confirmation, a prism-coupled configuration was used to excite the Dyakonov-Tamm wave guided by the interface of a dense thin film of magnesium fluoride and a chiral sculptured thin film of zinc selenide. The excitation was indicated by a reflection dip (with respect to the angle of incidence in the prism-coupled configuration) that is independent of the polarization state of the incident light as well as the thicknesses of both partnering materials beyond some thresholds. Applications to optical sensing and long-range on-chip communication are expected.An electromagnetic surface wave propagates along the interface of two dissimilar materials. The fields of the surface wave must not only satisfy the Maxwell equations in both partnering materials, but must also decay far away from the interface [1,3,2]. The localization of the fields to the interface makes surface-wave propagation sensitive to changes in the electromagnetic properties of the partnering materials in the region near the interface [3,4]. Such changes alter the field distribution, the phase speed, and the attenuation rate of the surface wave and may even cause the surface wave to disappear entirely. This sensitivity is most often exploited for optical sensing applications [4,7,5,6], but surface waves also show potential for applications in microscopy, photovoltaics, and communication [8,9,10].Most of these applications have been realized for surface-plasmon-polariton (SPP) waves, which requires one of the two partnering materials to be a metal whereas the other one is a dielectric material. The concept of these surface waves excited at optical frequencies arose in 1957, when Ritchie [11] presented a plasma-oscillation explanation for energy losses of fast electrons traversing thin metal films. Simple optical methods to launch these surface waves emerged shortly thereafter [12,14,13].Metals dissipate optical energy; hence, most SPP waves do not propagate long distances along the interface plane [15]. The replacement of the partnering metal by a dielectric material different from the other partner should reduce attenuation rates and enhance propagation distances. Indeed, a second type of electromagnetic surface wave was predicted in 1977 to be guided by the interface of two isotropic dielectric materials, at least one of which was periodically non-homogeneous in the direction perpendicular to the interface [16]. This surface wave is often called a Tamm wave as it is analogous to the electronic states predicted to exist at the interface of two crystals by Tamm in 1932 [17]. The experimental observation of Tamm waves followed in 1978 [18] and, more recently, their application to sensing has been demonstrated as well [5,6,19]. A third type of electromagnetic surface wave was predicted by Dyakonov in 1988 to be...

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Gas Laser in a Magnetic Field

Cited by 54 publications

References 52 publications

Electron spin-polarization in p-doped quantum wells

Electron spin-polarization in p-doped quantum wells

Spin-Dephasing Anisotropy for Electrons in a Diffusive Quasi-1D GaAs Wire

Observation of the Dyakonov-Tamm Wave

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