Local control of spin flow in weak magnetic fields (2008)
Astakhov, G. V., Ossau, W., Molenkamp, L. W., Heinrich, J., Hofling, S., ...
We demonstrate that optical illumination strongly influences spin transport in n-type GaAs. Specifically, increasing the power density of optical spin pumping results in a significant expansion of...
Non-thermal photocoercivity effect in a ferromagnetic semiconductor (2008)
Astakhov, G. V., Hoffmann, H., Korenev, V. L., Kiessling, T., Schwittek, J., Schott, G. M., ...
We report a photoinduced change of the coercive field, i.e., a photocoercivity effect (PCE), under very low intensity illumination of a low-doped (Ga,Mn)As ferromagnetic semiconductor. We find a...
Time-resolved and continuous-wave optical spin pumping of semiconductor quantum wells (2008)
Astakhov, G. V., Glazov, M. M., Yakovlev, D. R., Zhukov, E. A., Ossau, W., Molenkamp, L. W., ...
Experimental and theoretical studies of all-optical spin pump and probe of resident electrons in CdTe/(Cd,Mg)Te semiconductor quantum wells are reported. A two-color Hanle-MOKE technique (based on...
Suppression of electron spin relaxation in Mn-doped GaAs (2007)
Astakhov, G. V., Dzhioev, R. I., Kavokin, K. V., Korenev, V. L., Lazarev, M. V., Tkachuk, M. N., ...
We report a surprisingly long spin relaxation time of electrons in Mn-doped p-GaAs. The spin relaxation time scales with the optical pumping and increases from 12 ns in the dark to 160 ns upon...
Bound magnetic polarons in the very dilute regime (2007)
Kusrayev, Yu. G., Kavokin, K. V., Astakhov, G. V., Ossau, W., Molenkamp, L. W.
We study bound magnetic polarons (BMP) in a very diluted magnetic semiconductor CdMnTe by means of site selective spectroscopy. In zero magnetic field we detect a broad and asymmetric band with a...
C. Chory, R.B. Neder, V.I. Korsunskiy, F. Niederdraenk, C. Kumpf, ...
Journal article
Exciton spin decay modified by strong electron-hole exchange interaction (2006)
Astakhov, G. V., Koudinov, A. V., Kavokin, K. V., Gagis, I. S., Kusrayev, Yu. G., Ossau, W., ...
We study exciton spin decay in the regime of strong electron-hole exchange interaction. In this regime the electron spin precession is restricted within a sector formed by the external magnetic field...
Hoffmann, H., Astakhov, G. V., Kiessling, T., Ossau, W., Karczewski, G., Wojtowicz, T., ...
We report on optical spin pumping of modulation electrons in CdTe-based quantum wells with low intrinsic electron density (by 10^10 cm^{-2}). Under continuous wave excitation, we reach a steady state...
Anomalous in-plane magneto-optical anisotropy of self-assembled quantum dots (2006)
Kiessling, T., Platonov, A. V., Astakhov, G. V., Slobodskyy, T., Mahapatra, S., Ossau, W., ...
We report on a complex nontrivial behavior of the optical anisotropy of quantum dots that is induced by a magnetic field in the plane of the sample. We find that the optical axis either rotates in...
Keller, D., Yakovlev, D. R., Astakhov, G. V., Ossau, W., Crooker, S. A., Slobodskyy, T., ...
The optical properties of two-dimensional electron gases in ZnSe/(Zn,Be)Se and ZnSe/(Zn,Be,Mg)Se modulation-doped quantum wells with electron densities up to 1.4x10^{12} cm^{-2} were studied by...
Quantum-dot-based optical polarization conversion (2005)
Astakhov, G. V., Kiessling, T., Platonov, A. V., Slobodskyy, T., Mahapatra, S., Ossau, W., ...
We report circular-to-linear and linear-to-circular conversion of optical polarization by semiconductor quantum dots. The polarization conversion occurs under continuous wave excitation in absence of...
Kneip, M. K., Yakovlev, D. R., Bayer, M., Maksimov, A. A., Tartakovskii, I. I., Keller, D., ...
The dynamics of spin-lattice relaxation of the Mn-ions in (Zn,Mn)Se-based diluted-magnetic-semiconductor quantum wells is studied by time-resolved photoluminescence. The spin-lattice relaxation time...
Astakhov, G. V., Yakovlev, D. R., Rudenkov, V. V., Christianen, P. C. M., Barrick, T., Crooker, S. A., ...
The ground state of negatively charged excitons (trions) in high magnetic fields is shown to be a dark triplet state, confirming long-standing theoretical predictions. Photoluminescence (PL),...
Simple Estimation of X- Trion Binding Energy in Semiconductor Quantum Wells (2005)
Sergeev, R. A., Suris, R. A., Astakhov, G. V., Ossau, W., Yakovlev, D. R.
A simple illustrative wave function with only three variational parameters is suggested to calculate the binding energy of negatively charged excitons (X-) as a function of quantum well width. The...
Spin control in heteromagnetic nanostructures (2004)
Scherbakov, A. V., Akimov, A. V., Yakovlev, D. R., Ossau, W., Hansen, L., Waag, A., ...
The rapidly expanding research in Spintronics, the electronics utilizing the electron spin instead of its charge, is driven by the very interesting potential applications. The actual task is to...
Molecular-beam epitaxy of (Zn,Mn)Se on Si(100) (2004)
Slobodskyy, T., Rüster, C., Fiederling, R., Keller, D., Gould, C., Ossau, W., ...
We have investigated the growth by molecular-beam epitaxy of the II-VI diluted magnetic semiconductor (Zn,Mn)Se on As-passivated Si(100) substrates. The growth start has been optimized by using...
Fiederling, R., Grabs, P., Ossau, W., Schmidt, G., Molenkamp, L. W.
Detection of the degree of circular polarization of the electroluminescence of a light-emitting diode fitted with a spin injecting contact (a spin-LED) allows for a direct determination of the spin...
Worschech, L., Ossau, W., Landwehr, G.
Pres: 6th Int Symp Nanostructures: Physics and Technology, St Petersburg, Russia. 22-26 Jun 1998. p394. This article is from ADA406591 Nanostructures: Physics and Technology International Symposium...
Magnetic Field-Induced Type-I Type-II Transition in (ZuMu)Se/(ZaBe)Se Spin Superlattices (2002)
Koenig, B., Zehnder, U., Yakovlev, D. R., Ossau, W., Gerhard, T.
We have performed a magnetooptical study on spin superlattice structures fabricated on the basis of (ZnMn)Se/(ZnBe)Se. The band alignment of a Zn(0.91)Mn(0.09)Se/ Zn(0.972)Be(0.028)Se superlattice...
Magneto-Reflectivity Studies of ZnSe/ZnMgSSe QWs with Low Density 2DEG (2002)
Astakhov, G. A., Yakovlev, D. R., Kochereshko, V. P., Mikhailov, G. V., Ossau, W.
Magneto-reflectivity has been studied in modulation doped ZnSe/ZnMgSSe quantum well structures with low and moderate carrier concentrations. Negatively charged exciton (trion) lines were observed in...
Charged Excitons in ZnSe-Based QWs (2002)
Yakovlev, D. R., Astakhov, G. V., Kochereshko, V. P., Keller, A., Ossau, W.
We report on magneto-optical studies of ZnSe/(Zn,Mg)(S,Se) and ZnSe/(Zn,Be,Mg)Se quantum wells with n type and p type modulation doping. Negatively and positively charged excitons related to the...
Spectroscopy of Negatively Charged Excitons Interacting With 2DEG in CdTe/(Cd,Mg)Te QWs (2002)
Astakhov, G. V., Kochereshko, V. P., Yakovlev, D. R., Suris, R. A., Ossau, W.
We report on experimental observation of a combined exciton-electron processes in which an incident photon creates a trion (negatively charged exciton-electron complex) and promotes an inter-Landau...
Reflectivity Studies of Trion (X-) and Exciton (X) States in ZnSe/(Zn,Mg)(S,Se) QWs (2002)
Astakhov, G. A., Kochereshko, V. P., Yakovlev, D. R., Suris, R. A., Ossau, W.
The oscillator strength of negatively charged exciton (trion) in ZnSe/(Zn,Mg)(S,Se) quantum-well structures with n-type modulation doping is studied by reflection spectroscopy as a function of...
Gurevich, A. S., Kochereshko, V. P., Platonov, A. V., Yakovlev, D. R., Ossau, W.
Reflectivity and ellipsometry methods were applied to study optical properties of type-II ZnSe/BeTe superlattices. Natural in-plane optical anisotropy of the refractive and absorption indices has...
Optical Method for Determination of Carrier Density in Modulation Doped Quantum Wells (2001)
Astakhov, G. V., Kochereshko, V. P., Yakovlev, D. R., Ossau, W., Nurnberger, J., Faschinger, W., ...
An optical method is suggested to determine the concentration of two-dimensional electrons in modulation-doped quantum wells at low and moderate electron densities between 10^{9} and 2x10^{11}...
Binding Energy of Charged Excitons in ZnSe-based Quantum Wells (2001)
Astakhov, G. V., Yakovlev, D. R., Kochereshko, V. P., Ossau, W., Puls, J., Henneberger, F., ...
Excitons and charged excitons (trions) are investigated in ZnSe-based quantum well structures with (Zn,Be,Mg)Se and (Zn,Mg)(S,Se) barriers by means of magneto-optical spectroscopy. Binding energies...
Astakhov, G. V., Kosobukin, V. A., Kochereshko, V. P., Yakovlev, D. R., Ossau, W., Landwehr, G., ...
An approach is proposed to determine parameters of homogeneous and inhomogeneous broadening for reflection lines of quasi-two-dimensional excitons in semiconductor quantum well structures. A...
II-VI quantum structures with tunable electron g-factor (2000)
Wojtowicz, T., Kutrowski, M., Karczewski, G., Kossut, J., Konig, B., Keller, A., ...
Effect of spin-glass order on magnetic polarons in semimagnetic semiconductors (1997)
Chudnovskiy, A. L., Oppermann, R., Rosenow, B., Yakovlev, D. R., Zehnder, U., Ossau, W.
A theory accounting for the specific features of magnetic polarons (MP) in the presence of spin glass order is presented. We derive and solve selfconsistent equations for i) the polaron...
Combined exciton-cyclotron resonance in quantum well structures (1997)
Maan, J.C., Christianen, P.C.M., Landwehr, G., Waag, A., Ossau, W., Schenk, H., ...
Sol-gel synthesis and spectroscopic properties of thick nanocrystalline CdSe films (1997)
Ptatschek, V., Schreder, B., Herz, K., Hilbert, U., Ossau, W., Schottner, G., ...
Two novel metal alkoxide-derived routes ere developed for the synthesis of nanocrystalline CdSe layers with quantum dot sizes between 1 and 4nm. The first route, where cadmium ethoxy-acetate is...
TEMPERATURE AND MAGNETIC FIELD INDUCED BANDSTRUCTURE REVERSAL IN GaSb/AlSb QUANTUM WELLS (1987)
Forchel, A., Cebulla, U., TrÄnkle, G., Ossau, W., Griffiths, G., Subbanna, S., ...
We have investigated temperature and magnetic field induced changes in the occupation of the ϒ- and L-point minima of the conduction band of GaSb/ALSb quantum wells in the vicinity of the size...
TEMPERATURE AND MAGNETIC FIELD INDUCED BANDSTRUCTURE REVERSAL IN GaSb/AlSb QUANTUM WELLS (1987)
Forchel, A., Cebulla, U., TrÄnkle, G., Ossau, W., Griffiths, G., Subbanna, S., ...
We have investigated temperature and magnetic field induced changes in the occupation of the ϒ- and L-point minima of the conduction band of GaSb/ALSb quantum wells in the vicinity of the size...
TEMPERATURE AND MAGNETIC FIELD INDUCED BANDSTRUCTURE REVERSAL IN GaSb/AlSb QUANTUM WELLS (1987)
Forchel, A., Cebulla, U., TrÄnkle, G., Ossau, W., Griffiths, G., Subbanna, S., ...
We have investigated temperature and magnetic field induced changes in the occupation of the ϒ- and L-point minima of the conduction band of GaSb/ALSb quantum wells in the vicinity of the size...