Photoluminescence of a two-dimensional electron gas in a modulation-doped<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="normal">GaAs</mml:mi><mml:mo>/</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Al</mml:mi></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ga</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mi>−</mml:mi><mml:mi>x</mml:mi></mml:mrow></mml:

Ashkinadze, B. M.; Linder, E.; Cohen, E.; Dzyubenko, A. B.; Pfeiffer, L. N.

doi:10.1103/physrevb.69.115303

Cited by 12 publications

(12 citation statements)

References 36 publications

(61 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…16,17 Several effects might enhance the anomalies of the E 2D(B ) behavior observed in HJs. (a) As mentioned above, the hole distance from the interface deh varies with B .…”

Section: Discussionmentioning

confidence: 99%

Exciton to two-dimensional electron-hole photoluminescence transitions driven by the quantum Hall effect in photoexcited heterojunctions

et al. 2005

Self Cite

View full text Add to dashboard Cite

A comprehensive experimental study of the photoluminescence (PL) spectral evolution under a magnetic field (B ^ 25 T) applied perpendicularly to a high-mobility two-dimensional electron gas (2DEG), is performed on modulation-doped GaAs/AlGaAs heterojunctions at TL=0.3 K. The abrupt transfer of the free exciton to hole-2DEG PL occurring at integer and fractional filling factors is analyzed in a phenomenological model, wherein free excitons photogenerated in the GaAs layer dissociate into a 2D electron and 3D hole near the 2D-electron channel. Such magnetic field induced exciton-(2De-h) transitions are able to explain the remark able strong PL anomalies in single hetrojunctions as compared to those observed in modulation-doped quantum wells.

show abstract

“…16,17 Several effects might enhance the anomalies of the E 2D(B ) behavior observed in HJs. (a) As mentioned above, the hole distance from the interface deh varies with B .…”

Section: Discussionmentioning

confidence: 99%

Exciton to two-dimensional electron-hole photoluminescence transitions driven by the quantum Hall effect in photoexcited heterojunctions

et al. 2005

Self Cite

View full text Add to dashboard Cite

show abstract

“…A similar evolution from free 2DEG hole to excitonic transitions with increasing magnetic field has been reported previously by other authors. 12,20 The inset of Fig. 4 shows a double ͑or triple͒ peak feature changing the relative intensities of X s − ͑e1-hh1 , e1͒ and the other transitions in the range of magnetic fields between 13.0 and 13.5 T.…”

mentioning

confidence: 96%

“…[1][2][3][4][5][6][7][8][9] The photoluminescence ͑PL͒ spectroscopy is a useful tool in studying the many-body effect on interband optical transitions in QWs. In particular, a number of PL investigations [10][11][12][13] have observed that at a filling factor ͑=n e h / eB͒ of 2 ͑here n e , h, and B denote the electron density, the Planck constant, and the magnetic field, respectively͒, there is an abrupt change in the slope of the energy of the lowest Landau-level ͑LL͒ transition with line narrowing, indicating the formation of 2DEG-hole complexes. The transformation from a LL behavior to an excitonic one for Ͻ 2 has been explained by two different interpretations.…”

mentioning

confidence: 98%

Photoluminescence study of magnetic-field-induced excitonic transitions inAlxGa1−xAs∕GaAs

2007

View full text Add to dashboard Cite

We have observed magnetic-field-induced charged excitonic transitions from one-side-modulation-doped Al x Ga 1−x As/ GaAs asymmetric double quantum wells ͑ADQWs͒ where two low-energy conduction subbands e1 and e2 are coupled strongly, whereas the heavy-hole ground state hh1 is localized mostly in a quantum well.In the presence of a magnetic field applied parallel to the growth axis, the photoluminescence spectrum of the e1-hh1 transition develops into a Landau fan for filling factors of Ͼ 2. However, at Ͻ 2, the lowest Landaulevel ͑LL͒ transition reveals the charged-exciton behavior with an abrupt changeover in the field dependence of the transition energy, whereas the intensities of other LL transitions in the same Landau fan diminish. When the density of free electrons in the ADQWs is about 1.4ϫ 10 11 cm −2 , a new charged excitonic e2-hh1 transition also appears in the + polarization at Ͻ 2.The many-body interaction of a two-dimensional electron gas ͑2DEG͒ in modulation-doped quantum wells ͑QWs͒ has been the subject of extensive investigations in the past years. 1-9 The photoluminescence ͑PL͒ spectroscopy is a useful tool in studying the many-body effect on interband optical transitions in QWs. In particular, a number of PL investigations 10-13 have observed that at a filling factor ͑=n e h / eB͒ of 2 ͑here n e , h, and B denote the electron density, the Planck constant, and the magnetic field, respectively͒, there is an abrupt change in the slope of the energy of the lowest Landau-level ͑LL͒ transition with line narrowing, indicating the formation of 2DEG-hole complexes. The transformation from a LL behavior to an excitonic one for Ͻ 2 has been explained by two different interpretations.According to an interpretation in terms of the screening effect, 4 the transition of electron-hole ͑e-h͒ plasma into exciton, the so-called exciton-Mott transition, occurs when the density of plasma is decreased below a critical value. A similar transition can occur in QWs containing 2DEG and a photogenerated hole when the density of electrons is decreased. At a high electron density of n e ജ 1/a B 2 ͑here, a B is the Bohr radius of exciton in the QW͒, the e-h Coulomb interaction is screened effectively by free carriers, resulting in the prohibition of exciton formation. The critical electron density for the transition of electron-plasma into exciton increases in the presence of a magnetic field. Since the magnetic field shrinks the wave function of an electronic bound state, the screening effect on the e-h Coulomb interaction is reduced, allowing the formation of many-electrons-hole complexes such as X − the negatively charged exciton. 14,15 According to this mechanism, there is no difference between symmetric and asymmetric QWs in the changeover from a LL behavior to an excitonic behavior.On the other hand, a rather recent theory explains the abrupt changeover from LL behaviors to excitonic behaviors in both energy and linewidth as a consequence of hidden symmetry 11 ͑HS͒ inherent in a symmetric 2DEG system in strong magneti...

show abstract

“…Golub for helpful discussions on the issues of the spin relaxation of holes in quantum wells, to B.M. Ashkinadze for providing the previously studied sample 20,24,29 …”

Section: Acknowledgementsmentioning

confidence: 99%

Optical spin orientation of minority holes in a modulation-doped GaAs/(Ga,Al)As quantum well

et al. 2016

View full text Add to dashboard Cite

The optical spin orientation effect in a GaAs/(Ga,Al)As quantum well containing a high-mobility 2D electron gas was found to be due to spin-polarized minority carriers, the holes. The observed oscillations of both the intensity and polarization of the photoluminescence in a magnetic field are well described in a model whose main elements are resonant absorption of the exciting light by the Landau levels and mixing of the heavy-and light-hole subbands. After subtraction of these effects, the observed influence of magnetic fields on the spin polarization can be well interpreted by a standard approach of the optical orientation method. The spin relaxation of holes is controlled by the Dyakonov-Perel' mechanism. Deceleration of the spin relaxation by the magnetic field occurs through the Ivchenko mechanism -due to the cyclotron motion of holes. Mobility of holes was found to be two orders of magnitude smaller than that of electrons, being determined by the scattering of holes upon the electron gas.

show abstract

Photoluminescence of a two-dimensional electron gas in a modulation-dopedGaAs/AlxGa1−x

Cited by 12 publications

References 36 publications

Exciton to two-dimensional electron-hole photoluminescence transitions driven by the quantum Hall effect in photoexcited heterojunctions

Exciton to two-dimensional electron-hole photoluminescence transitions driven by the quantum Hall effect in photoexcited heterojunctions

Photoluminescence study of magnetic-field-induced excitonic transitions inAlxGa1−xAs∕GaAs

Optical spin orientation of minority holes in a modulation-doped GaAs/(Ga,Al)As quantum well

Contact Info

Product

Resources

About