Interference of polariton waves in structures with wide GaAs/AlGaAs quantum wells

Reflectivity spectra taken from wide quantum wells based on CdTe/CdZnTe and GaAs/AlGaAs (in which the well width is much larger than the exciton Bohr radius) were studied in magnetic fields in the plane of the well (the Voigt geometry). The energy splitting between bright and dark excitons and the redistribution of the oscillator strength from bright to dark was observed and this allowed us to determine the exciton exchange constant ∆. We found that exciton translational mass depends on the value of magnetic field. Additionally, we found that diamagnetic shift also depends on exciton wave vector. Changes in the spectra in the range of the overlap of heavy and light hole exciton resonances were observed when the magnetic field was inverted. Theoretical modeling of the spectra allowed us to explain all the observed features in the reflectivity spectra and to determine some material parameters.

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“…We performed calculations of these spectra as in paper [3]. The results of the calculations are shown by dotted lines in Figs.…”

Section: Resultsmentioning

confidence: 99%

“…excitons in motion [1,2]. Due to size quantization, features of exciton states with nonzero wave vector emerge in optical spectra [3]. Exciton motion in a magnetic field is particularly interesting for fundamental science because many new optical effects can be expected.…”

Section: Introductionmentioning

confidence: 99%

Excitonic Polaritons in Transverse Magnetic Fields

et al. 2007

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“…From the spectra it is obvious that the magnitude of the Zeeman splitting for light exciton states increases as the quantization number grows. From the spectra we extracted different excitonic parameters, such as the g-factor and the diamagnetic constant d [8]. Figure 1b shows the dependence of the light exciton magnetic moment on its wave vector.…”

Section: Resultsmentioning

confidence: 99%

Motional Enhancement of Exciton Magnetic Moments

et al. 2007

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“…[2,16,19,10]. We assume that the incident light is directed perpendicular to the sample surface and linearly polarized along one of the optical anisotropy axes.…”

Section: Original Papermentioning

confidence: 99%

“…An efficient approach to the analysis of the exciton optical response is the polaritonic model, which accounts for the modification of exciton dispersion due to its coupling to light, thus allowing one to model the reflectivity spectra [10,[15][16][17][18][19]. Previous studies have clearly shown that the dispersion is weakly affected by the QW confinement for the well width of L QW > 6a B , where a B is the exciton Bohr radius [6].…”

Section: Introductionmentioning

confidence: 99%

Reduction of exciton mass by uniaxial stress in GaAs/AlGaAs quantum wells

Loginov

Grigoryev

Efimov

et al. 2016

Phys. Status Solidi B

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Abstractauthoren We show experimentally that the uniaxial stress applied along the twofold symmetry axis of a high‐quality heterostructure containing a wide GaAs/AlGaAs quantum well leads to considerable modification of the exciton‐polariton reflectivity spectra. We observe: (i) the energy splitting of the light‐hole and heavy‐hole exciton resonances to appear and (ii) the increase of the quasiperiod (divergence) of spectral oscillations related to the optically allowed exciton‐polariton transitions. A theoretical analysis shows that the first effect is due to the strain‐induced reduction of crystal symmetry. The divergence of spectral oscillations is found to be due to the strain‐induced decrease of the heavy‐hole exciton mass. The effective mass is reduced by 5% at the pressure of P=0.23GPa. This effect shows the potentiality of spectroscopic ways of strain detection in semiconductors.

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Interference of polariton waves in structures with wide GaAs/AlGaAs quantum wells

Cited by 14 publications

References 16 publications

Excitonic Polaritons in Transverse Magnetic Fields

Excitonic Polaritons in Transverse Magnetic Fields

Motional Enhancement of Exciton Magnetic Moments

Reduction of exciton mass by uniaxial stress in GaAs/AlGaAs quantum wells

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