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Petr Klenovský - One of the best experts on this subject based on the ideXlab platform.

  • excitonic structure and pumping power dependent emission Blue Shift of type ii quantum dots
    Scientific Reports, 2017
    Co-Authors: Petr Klenovský, Petr Steindl, Dominique Alain Geffroy
    Abstract:

    In this work we study theoretically and experimentally the multi-particle structure of the so-called type-II quantum dots with spatially separated electrons and holes. Our calculations based on customarily developed full configuration interaction ap- proach reveal that exciton complexes containing holes interacting with two or more electrons exhibit fairly large antibinding energies. This effect is found to be the hallmark of the type-II confinement. In addition, an approximate self-consistent solution of the multi-exciton problem allows us to explain two pronounced phenomena: the Blue-Shift of the emission with pumping and the large inhomogeneous spectral broadening, both of those eluding explanation so far. The results are confirmed by detailed intensity and polarization resolved photoluminescence measurements on a number of type-II samples.

  • excitonic structure and pumping power dependent emission Blue Shift of type ii quantum dots
    arXiv: Mesoscale and Nanoscale Physics, 2016
    Co-Authors: Petr Klenovský, Petr Steindl, Dominique Geffroy
    Abstract:

    In this work we study theoretically and experimentally the multi-particle structure of the so-called type-II quantum dots with spatially separated electrons and holes. Our calculations based on customarily developed full configuration interaction approach reveal that exciton complexes containing holes interacting with two or more electrons exhibit fairly large antibinding energies. This effect is found to be the hallmark of the type-II confinement. In addition, an approximate self-consistent solution of the multi-exciton problem allows us to explain two pronounced phenomena: the Blue-Shift of the emission with pumping and the large inhomogenous spectral broadening, both of those eluding explanation so far. The results are confirmed by detailed intensity and polarization resolved photoluminescence measurements on a number of type-II samples.

Rainer Leonhardt - One of the best experts on this subject based on the ideXlab platform.

  • Anomalous Blue-Shift of terahertz whispering-gallery modes via dielectric and metallic tuning
    Optics letters, 2019
    Co-Authors: Dominik Walter Vogt, Angus Harvey Jones, Harald G. L. Schwefel, Rainer Leonhardt
    Abstract:

    The vast majority of resonant systems show a red-Shift for the resonance frequency when a perturbation, e.g. losses, are introduced to the system. In contrast, here we report for the first time the experimental demonstration of both red- and anomalous Blue-Shifting of whispering-gallery modes (WGMs) using dielectric and metallic substrates. The maximum Blue-Shift is more than three times as large as the expected red-Shift, proving that the anomalous Blue-Shift is more than a peculiar curiosity. The experiments are performed in the terahertz (THz) frequency range with coherent continuous-wave spectroscopy. The results establish dielectric and metallic tuning as a novel, and viable approach to tune high quality (high-Q) WGMs, and provide valuable insights into the anomalous Blue-Shift of WGM cavity systems. The tuning capabilities for these compact monolithic resonators is of significant interest for fundamental science and technological applications alike.

  • Anomalous Blue-Shift of terahertz whispering-gallery modes
    2019 44th International Conference on Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2019
    Co-Authors: Dominik Walter Vogt, Angus Harvey Jones, Harald G. L. Schwefel, Rainer Leonhardt
    Abstract:

    We report on the first demonstration of an anomalous Blue-Shift of whispering-gallery modes (WGMs) using metallic substrates. The results allow for frequency tuning of WGMs essential for numerous applications, and establish novel insights into the anomalous Blue-Shift of WGM cavity systems.

Mihalis Dafermos - One of the best experts on this subject based on the ideXlab platform.

  • time translation invariance of scattering maps and Blue Shift instabilities on kerr black hole spacetimes
    Communications in Mathematical Physics, 2017
    Co-Authors: Mihalis Dafermos, Yakov Shlapentokhrothman
    Abstract:

    In this paper, we provide an elementary, unified treatment of two distinct Blue-Shift instabilities for the scalar wave equation on a fixed Kerr black hole background: the celebrated Blue-Shift at the Cauchy horizon (familiar from the strong cosmic censorship conjecture) and the time-reversed red-Shift at the event horizon (relevant in classical scattering theory). Our first theorem concerns the latter and constructs solutions to the wave equation on Kerr spacetimes such that the radiation field along the future event horizon vanishes and the radiation field along future null infinity decays at an arbitrarily fast polynomial rate, yet, the local energy of the solution is infinite near any point on the future event horizon. Our second theorem constructs solutions to the wave equation on rotating Kerr spacetimes such that the radiation field along the past event horizon (extended into the black hole) vanishes and the radiation field along past null infinity decays at an arbitrarily fast polynomial rate, yet, the local energy of the solution is infinite near any point on the Cauchy horizon. The results make essential use of the scattering theory developed in Dafermos, Rodnianski and Shlapentokh-Rothman (A scattering theory for the wave equation on Kerr black hole exteriors (2014). arXiv:1412.8379) and exploit directly the time-translation invariance of the scattering map and the non-triviality of the transmission map.

  • time translation invariance of scattering maps and Blue Shift instabilities on kerr black hole spacetimes
    arXiv: General Relativity and Quantum Cosmology, 2015
    Co-Authors: Mihalis Dafermos, Yakov Shlapentokhrothman
    Abstract:

    In this paper, we provide an elementary, unified treatment of two distinct Blue-Shift instabilities for the scalar wave equation on a fixed Kerr black hole background: the celebrated Blue-Shift at the Cauchy horizon (familiar from the strong cosmic censorship conjecture) and the time-reversed red-Shift at the event horizon (relevant in classical scattering theory). Our first theorem concerns the latter and constructs solutions to the wave equation on Kerr spacetimes such that the radiation field along the future event horizon vanishes and the radiation field along future null infinity decays at an arbitrarily fast polynomial rate, yet, the local energy of the solution is infinite near any point on the future event horizon. Our second theorem constructs solutions to the wave equation on rotating Kerr spacetimes such that the radiation field along the past event horizon (extended into the black hole) vanishes and the radiation field along past null infinity decays at an arbitrarily fast polynomial rate, yet, the local energy of the solution is infinite near any point on the Cauchy horizon. The results make essential use of the scattering theory developed in [M. Dafermos, I. Rodnianski and Y. Shlapentokh-Rothman, A scattering theory for the wave equation on Kerr black hole exteriors, preprint (2014) available at \url{this http URL}] and exploit directly the time-translation invariance of the scattering map and the non-triviality of the transmission map.

Petr Steindl - One of the best experts on this subject based on the ideXlab platform.

  • excitonic structure and pumping power dependent emission Blue Shift of type ii quantum dots
    Scientific Reports, 2017
    Co-Authors: Petr Klenovský, Petr Steindl, Dominique Alain Geffroy
    Abstract:

    In this work we study theoretically and experimentally the multi-particle structure of the so-called type-II quantum dots with spatially separated electrons and holes. Our calculations based on customarily developed full configuration interaction ap- proach reveal that exciton complexes containing holes interacting with two or more electrons exhibit fairly large antibinding energies. This effect is found to be the hallmark of the type-II confinement. In addition, an approximate self-consistent solution of the multi-exciton problem allows us to explain two pronounced phenomena: the Blue-Shift of the emission with pumping and the large inhomogeneous spectral broadening, both of those eluding explanation so far. The results are confirmed by detailed intensity and polarization resolved photoluminescence measurements on a number of type-II samples.

  • excitonic structure and pumping power dependent emission Blue Shift of type ii quantum dots
    arXiv: Mesoscale and Nanoscale Physics, 2016
    Co-Authors: Petr Klenovský, Petr Steindl, Dominique Geffroy
    Abstract:

    In this work we study theoretically and experimentally the multi-particle structure of the so-called type-II quantum dots with spatially separated electrons and holes. Our calculations based on customarily developed full configuration interaction approach reveal that exciton complexes containing holes interacting with two or more electrons exhibit fairly large antibinding energies. This effect is found to be the hallmark of the type-II confinement. In addition, an approximate self-consistent solution of the multi-exciton problem allows us to explain two pronounced phenomena: the Blue-Shift of the emission with pumping and the large inhomogenous spectral broadening, both of those eluding explanation so far. The results are confirmed by detailed intensity and polarization resolved photoluminescence measurements on a number of type-II samples.

Yuanhong Liu - One of the best experts on this subject based on the ideXlab platform.

  • Blue Shift of spectrum and enhanced luminescent properties of yag ce3 phosphor induced by small amount of la3 incorporation
    Journal of Alloys and Compounds, 2016
    Co-Authors: Jiyou Zhong, Weidong Zhuang, Yaling Zheng, Ligen Wang, Xianran Xing, Ronghui Liu, Yuanhong Liu
    Abstract:

    Abstract A gradual Blue-Shift of spectrum in YAG: Ce3+ phosphor induced by small amount of La3+ co-doping was observed. The luminescent efficiency and thermal quenching properties were enhanced by appropriate amount of La3+ incorporation. The possible mechanism of these changes in luminescent properties was investigated by luminescence dynamics analysis and first principles calculation on structure optimization. The results demonstrate that the local structural variation around Ce3+ ions may be responsible for the Blue-Shift of spectrum and enhanced luminescent properties, which produces a relatively stable environment for Ce3+ ions and prevents concentration quenching. The above results indicate that appropriate amount of La3+ co-doing is beneficial to luminescent properties enhancement of YAG: Ce3+ phosphor and it is expected to be extended in other Ce3+-activated garnet phosphors.