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Ortner G Bayer M Lyanda-Geller Y Reinecke TL Kress A Reithmaier JP Forchel A 《Physical review letters》2005,94(15):157401
Controllable interactions that couple quantum dots are a key requirement in the search for scalable solid state implementations for quantum information technology. From optical studies of excitons and corresponding calculations, we demonstrate that an electric field on vertically coupled pairs of In(0.6)Ga(0.4)As/GaAs quantum dots controls the mixing of the exciton states on the two dots and also provides controllable coupling between carriers in the dots. 相似文献
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G. Ortner M. Bayer A. Kress A. Forchel Y. B. Lyanda-Geller T. L. Reinecke 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):171
Semiconductor nanostructures have attracted considerable interest during the recent years in view of the potential application in quantum information processing. In particular, quantum dots have been suggested to fulfill an essential requirement for quantum computation: controllable interaction that couples two quantum dot qubits. Previous experiments on two vertically aligned quantum dots have demonstrated the formation of coupled exciton states. We show that this coupling between two In0.60Ga0.40As/GaAs quantum dots can be tuned by an electric field applied along the molecule axis. This controllable coupling in such a relatively simple configuration could be implemented in a solid-state-based quantum device. 相似文献
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Yuli Lyanda-Geller J. P. Leburton 《Physica E: Low-dimensional Systems and Nanostructures》1998,2(1-4)
We demonstrate the possibility of oscillations of magnetic peak positions of the Stark-cyclotron resonance due to acoustic phonon scattering in confined superlattices and investigate oscillations of the hopping current in the Wannier–Stark localization regime due to phonon folding and electron Bragg reflection. Manifestation of these effects in recent experiments is discussed. 相似文献
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Rokhinson LP Larkina V Lyanda-Geller YB Pfeiffer LN West KW 《Physical review letters》2004,93(14):146601
Charged carriers with different spin states are spatially separated in a two-dimensional hole gas. Because of strong spin-orbit interaction, holes at the Fermi energy in GaAs have different momenta for two possible spin states traveling in the same direction, and, correspondingly, different cyclotron orbits in a weak magnetic field. Two point contacts, acting as a monochromatic source of ballistic holes and a narrow detector arranged in the magnetic focusing geometry are demonstrated to work as a tunable spin filter. 相似文献
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Leonid P. Rokhinson Mason Overby Alexandr Chernyshov Yuli Lyanda-Geller Xinyu Liu Jacek K. Furdyna 《Journal of magnetism and magnetic materials》2012
We report experiments where magnetization in GaMnAs ferromagnetic semiconductor is manipulated via strain or electric current. In both cases, charge carrier holes become partially polarized due to the anisotropic modification of holes spectra caused by spin–orbit interactions, and this polarization exerts spin torque sufficient to rotate ferromagnetic domains. 相似文献
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Ware ME Stinaff EA Gammon D Doty MF Bracker AS Gershoni D Korenev VL Bădescu SC Lyanda-Geller Y Reinecke TL 《Physical review letters》2005,95(17):177403
We report polarized photoluminescence excitation spectroscopy of the negative trion in single charge-tunable quantum dots. The spectrum exhibits a p-shell resonance with polarized fine structure arising from the direct excitation of the electron spin triplet states. The energy splitting arises from the axially symmetric electron-hole exchange interaction. The magnitude and sign of the polarization are understood from the spin character of the triplet states and a small amount of quantum dot asymmetry, which mixes the wave functions through asymmetric e-e and e-h exchange interactions. 相似文献
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While low-temperature Hall resisitivity rhoxy of La2/3(Ca,Pb)1/3MnO3 single crystals can be separated into ordinary (OHE) and anomalous (AHE) contributions, no such decomposition is possible near the Curie temperature Tc. Rather, the rhoxy data collapse to a single function of the reduced magnetization m=M/Msat, with an extremum at approximately 0.4 m. A new mechanism for the AHE in the inelastic hopping regime is identified that reproduces the scaling curve. An extension of Holstein's model for the hopping OHE, the mechanism arises from the combined effects of the double-exchange-induced quantal phase in triads of Mn ions and spin-orbit interactions. 相似文献
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Ortner G Bayer M Larionov A Timofeev VB Forchel A Lyanda-Geller YB Reinecke TL Hawrylak P Fafard S Wasilewski Z 《Physical review letters》2003,90(8):086404
Exciton fine structure in InAs/GaAs coupled quantum dots has been studied by photoluminescence spectroscopy in magnetic fields up to 8 T. Pronounced anticrossings and mixings of optically bright and dark states as functions of magnetic field are seen. A theoretical treatment of the mixing of the excitonic states has been developed, and it traces observed features to structural asymmetries. These results provide direct evidence for coherent coupling of excitons in quantum dot molecules. 相似文献