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1

Structural and Optical Studies of CdTe/ZnTe Superlattices with Ultrathin ZnTe Layers

100%

Mariette H., Jouneau P., Pelekanos N., Tardot A., Feuilet G., Magnea N.

Acta Physica Polonica A

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1993

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vol. 84

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issue 3

423-433

EN

Spatially selective introduction of ultrathin ZnTe layers (1 to 3 mono-layers) into CdTe allows the study of special superlattice structure, corresponding to a monomolecular plane-host crystal system. Particular attention is given to the strain state control of the inserted ZnTe monolayer. High resolution electron microscopy is used to measure the local lattice distortion: the method yields the location and the total amount of Zn per period, and the results are compared with X-ray diffraction data. Optical properties of these superlattices are also presented. All results show the ability to control ultrathin pseudomorphic layers of ZnTc within CdTe, with limited Zn segregation, and of high crystalline and optical quality. In addition, they can be fitted within the framework of elasticity theory for the structural data, and of a finite quantum well model for the optical ones, even in the ultimate limit of only one nominal ZnTe monolayer.

2

Optical Properties of Manganese-Doped Individual CdTe Quantum Dots

100%

Besombes L., Léger Y., Maingault L., Ferrand D., Bougerol C., Mariette H., Cibert J.

Acta Physica Polonica A

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2005

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vol. 108

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issue 4

527-540

EN

The magnetic state of a single magnetic ion (Mn^{2+}) embedded in an individual quantum dot is optically probed using microspectroscopy. The fine structure of a confined exciton in the exchange field of a single Mn^{2+} ion (S=5/2) is analyzed in detail. The exciton-Mn^{2+} exchange interaction shifts the energy of the exciton depending on the Mn^{2+} spin component and six emission lines are observed at zero magnetic field. The emission spectra of individual quantum dots containing a single magnetic Mn atom differ strongly from dot to dot. The differences are explained by the influence of the system geometry, specifically the in-plane asymmetry of the quantum dot and the position of the Mn atom. Depending on both these parameters, one has different characteristic emission features which either reveal or hide the spin state of the magnetic atom. The observed behavior in both zero field and under magnetic field can be explained quantitatively by the interplay between the exciton-manganese exchange interaction (dependent on the Mn position) and the anisotropic part of the electron-hole exchange interaction (related to the asymmetry of the quantum dot).

3

Photon Correlations and Cross-Correlations from a Single CdTe/ZnTe Quantum Dot

84%

Couteau C., Moehl S., Suffczyński J., Gaj J., Tinjod F., Gérard J., Kheng K., Mariette H., Romestain R., Poizat J.

Acta Physica Polonica A

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2004

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vol. 106

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issue 2

169-176

EN

We report correlation and cross-correlation continuous wave measurements in II-VI quantum dots grown by molecular beam epitaxy. Combination of spectral selection, saturation measurements and good temporal resolution allowed us to see an antibunching effect on photons from radiative recombination of excitons in a single CdTe/ZnTe quantum dot, as well as cross-correlation within the biexciton (X_{2})-exciton (X) radiative cascade from the same dot. We discuss the results of our experiments in terms of a model of excitonic multitransitions.

4

Motional Enhancement of Exciton Magnetic Moments

84%

Litvinov A., Kochereshko V., Cox R., Besombes L., Mariette H., Boukari H., Loginov D., Davies J., Smith L., Wolverson D.

Acta Physica Polonica A

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2007

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vol. 112

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issue 2

161-165

EN

The phenomenon in which giant enhancement of exciton magnetic moments occurs due to translational motion was found for light hole excitons in ZnTe/ZnMgTe quantum well structures. Decreasing diamagnetic shifts as the number of the exciton quantized state increases were found for the first time.

5

Excitonic Polaritons in Transverse Magnetic Fields

84%

Loginov D., Kochereshko V., Litvinov A., Besombes L., Mariette H., Davies J., Smith L., Wolverson D.

Acta Physica Polonica A

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2007

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vol. 112

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issue 2

381-386

EN

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 constantΔ. 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.

6

Raman Characterization of MBE-Grown Layered MnTe/CdTe Structures

68%

Szuszkiewicz W., Jouanne M., Morhange J. F., Kanehisa M. A., Mariette H., Hartmann J. M., Dynowska E., Karczewski G., Wojtowicz T., Kossut J., Barnaś J.

Acta Physica Polonica A

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1997

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vol. 92

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issue 5

1021-1024

EN

Raman scattering measurements on (MnTe)_{8}/(Cd_{0.64}Zn_{0.36}Te)_{8} multilayer grown by MBE method and on various (MnTe)_{n}/(CdTe)_{12} multilayers (where n=8,12,16,24) were performed at low temperatures. In the z̅(x,x)z polarization, structures corresponding to folded acoustic phonons were found. In z̅(x,y)z polarization new complex structures were observed in the low-frequency part of Raman scattering spectra. A possible magnetic origin of these structures is discussed.

Refine search results

Structural and Optical Studies of CdTe/ZnTe Superlattices with Ultrathin ZnTe Layers

Optical Properties of Manganese-Doped Individual CdTe Quantum Dots

Photon Correlations and Cross-Correlations from a Single CdTe/ZnTe Quantum Dot

Motional Enhancement of Exciton Magnetic Moments

Excitonic Polaritons in Transverse Magnetic Fields

Raman Characterization of MBE-Grown Layered MnTe/CdTe Structures