The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Arshad Saleem Bhatti - One of the best experts on this subject based on the ideXlab platform.
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spin orbit coupling effect on Energy Level Splitting and band structure inversion in cspbbr 3
Journal of Materials Science, 2021Co-Authors: Mujtaba Hussain, Muhammad Rashid, Faisal Saeed, Arshad Saleem BhattiAbstract:The band structures and density of states (DOS) of all the three structural configurations of CsPbBr3 without spin–orbit coupling (SOC = 0) and with the addition of spin–orbit coupling (SOC ≠ 0) effects were calculated, using density functional theory. Upon the inclusion of the spin–orbit coupling, the bandgaps exhibit reductions of 1.27 eV, 1.16 eV and 1.08 eV for the cubic, tetragonal and orthorhombic phases, respectively. These calculations provide a positive split-off Energy value of Δso = 1.69 eV for the simple cubic phase. For the lower symmetry phases, the p-like fourfold degenerate $$\varGamma_{8v}^{(4)}$$ band has been observed to split to form two bands, in addition to the $$\varGamma_{6v}^{(2)}$$ split-off band. The calculated Splitting energies between these bands are found to be in close agreement with previous experimentally measured values. The calculated electronic band structures show that CsPbBr3 has a negative ‘inversion Energy’ (Δi < 0). The magnitude of the inversion Energy for the cubic phase is 2.36 eV for SOC = 0, which increased by 0.4–2.76 eV with the addition of the spin–orbit coupling. The arrangement of Bloch Levels in the band structure of CsPbBr3 has been found to resemble that of a typical topological semimetal, but with a nonzero bandgap opening, due to the presence of the inversion asymmetry within its molecular structure.
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Spin–orbit coupling effect on Energy Level Splitting and band structure inversion in CsPbBr 3
Journal of Materials Science, 2020Co-Authors: Mujtaba Hussain, Muhammad Rashid, Faisal Saeed, Arshad Saleem BhattiAbstract:The band structures and density of states (DOS) of all the three structural configurations of CsPbBr3 without spin–orbit coupling (SOC = 0) and with the addition of spin–orbit coupling (SOC ≠ 0) effects were calculated, using density functional theory. Upon the inclusion of the spin–orbit coupling, the bandgaps exhibit reductions of 1.27 eV, 1.16 eV and 1.08 eV for the cubic, tetragonal and orthorhombic phases, respectively. These calculations provide a positive split-off Energy value of Δso = 1.69 eV for the simple cubic phase. For the lower symmetry phases, the p-like fourfold degenerate $$\varGamma_{8v}^{(4)}$$ band has been observed to split to form two bands, in addition to the $$\varGamma_{6v}^{(2)}$$ split-off band. The calculated Splitting energies between these bands are found to be in close agreement with previous experimentally measured values. The calculated electronic band structures show that CsPbBr3 has a negative ‘inversion Energy’ (Δi
Kelly M. Patton - One of the best experts on this subject based on the ideXlab platform.
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Stimulated neutrino transformation with sinusoidal density profiles
Journal of Physics G: Nuclear and Particle Physics, 2013Co-Authors: James P. Kneller, Gail C. Mclaughlin, Kelly M. PattonAbstract:Large amplitude oscillations between the states of a quantum system can be stimulated by sinusoidal external potentials with frequencies that are similar to the Energy Level Splitting of the states or a fraction thereof. Situations where the applied frequency is equal to an integer fraction of the Energy Level Splittings are known as parametric resonances. We investigate this effect for neutrinos both analytically and numerically for the case of arbitrary numbers of neutrino flavors. We look for environments where the effect may be observed and find that supernovae are the one realistic possibility due to the necessity of both large densities and large amplitude fluctuations. In conclusion, the comparison of numerical and analytical results of neutrino propagation through a model supernova reveals that it is possible to predict the locations and strengths of the stimulated transitions that occur.
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Stimulated Neutrino Transformation in Supernovae
arXiv: High Energy Physics - Phenomenology, 2012Co-Authors: James P. Kneller, Gail C. Mclaughlin, Kelly M. PattonAbstract:Large amplitude oscillations between states of a quantum system can be stimulated by sinusoidal external potentials with frequencies that are equal to the Energy Level Splitting of the states or a fraction thereof. We investigate this effect for neutrino oscillations both analytically and numerically finding a simple expression for amplitude and wavelength of the transitions as a function of the density, the amplitude and wavenumber of the fluctuation, and the matter mixing matrix elements. We apply our findings to the supernova environment and find that it is possible to predict stimulated transitions that occur due to sinusoidal perturbations in the density.
Mujtaba Hussain - One of the best experts on this subject based on the ideXlab platform.
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spin orbit coupling effect on Energy Level Splitting and band structure inversion in cspbbr 3
Journal of Materials Science, 2021Co-Authors: Mujtaba Hussain, Muhammad Rashid, Faisal Saeed, Arshad Saleem BhattiAbstract:The band structures and density of states (DOS) of all the three structural configurations of CsPbBr3 without spin–orbit coupling (SOC = 0) and with the addition of spin–orbit coupling (SOC ≠ 0) effects were calculated, using density functional theory. Upon the inclusion of the spin–orbit coupling, the bandgaps exhibit reductions of 1.27 eV, 1.16 eV and 1.08 eV for the cubic, tetragonal and orthorhombic phases, respectively. These calculations provide a positive split-off Energy value of Δso = 1.69 eV for the simple cubic phase. For the lower symmetry phases, the p-like fourfold degenerate $$\varGamma_{8v}^{(4)}$$ band has been observed to split to form two bands, in addition to the $$\varGamma_{6v}^{(2)}$$ split-off band. The calculated Splitting energies between these bands are found to be in close agreement with previous experimentally measured values. The calculated electronic band structures show that CsPbBr3 has a negative ‘inversion Energy’ (Δi < 0). The magnitude of the inversion Energy for the cubic phase is 2.36 eV for SOC = 0, which increased by 0.4–2.76 eV with the addition of the spin–orbit coupling. The arrangement of Bloch Levels in the band structure of CsPbBr3 has been found to resemble that of a typical topological semimetal, but with a nonzero bandgap opening, due to the presence of the inversion asymmetry within its molecular structure.
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Spin–orbit coupling effect on Energy Level Splitting and band structure inversion in CsPbBr 3
Journal of Materials Science, 2020Co-Authors: Mujtaba Hussain, Muhammad Rashid, Faisal Saeed, Arshad Saleem BhattiAbstract:The band structures and density of states (DOS) of all the three structural configurations of CsPbBr3 without spin–orbit coupling (SOC = 0) and with the addition of spin–orbit coupling (SOC ≠ 0) effects were calculated, using density functional theory. Upon the inclusion of the spin–orbit coupling, the bandgaps exhibit reductions of 1.27 eV, 1.16 eV and 1.08 eV for the cubic, tetragonal and orthorhombic phases, respectively. These calculations provide a positive split-off Energy value of Δso = 1.69 eV for the simple cubic phase. For the lower symmetry phases, the p-like fourfold degenerate $$\varGamma_{8v}^{(4)}$$ band has been observed to split to form two bands, in addition to the $$\varGamma_{6v}^{(2)}$$ split-off band. The calculated Splitting energies between these bands are found to be in close agreement with previous experimentally measured values. The calculated electronic band structures show that CsPbBr3 has a negative ‘inversion Energy’ (Δi
Huijing Zhang - One of the best experts on this subject based on the ideXlab platform.
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Energy-Level Splitting of ligand-stabilized Au55 clusters observed by scanning tunneling spectroscopy
Applied Physics Letters, 2004Co-Authors: Huijing Zhang, Uwe Hartmann, G. SchmidAbstract:A monolayer of Au55 clusters stabilized by [P(C6H5)3]12Cl6 ligands was investigated at 7 K using a low-temperature ultrahigh vacuum scanning tunneling microscope. The topography of single clusters shows the actual arrangement of the C6H5 rings of ligand molecules. Characteristic charge-quantization phenomena usually obtained for metal particles were observed by current–voltage measurements. Spectroscopic data acquired at different locations within a cluster reveal Energy Levels with average spacing of 170 meV which can be attributed to the Au55 core.
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Energy Level Splitting of ligand stabilized au55 clusters observed by low temperature scanning tunneling spectroscopy
SCANNING TUNNELING MICROSCOPY SPECTROSCOPY AND RELATED TECHNIQUES: 12th International Conference STM'03, 2003Co-Authors: Huijing Zhang, Holger Grzeschik, Pranab Kumar Sarkar, Michael Springborg, Uwe HartmannAbstract:Low‐temperature ultrahigh‐vacuum (UHV) scanning tunneling microscopy (STM) and spectroscopy (STS) were employed to analyze the electronic structure of Au55 clusters stabilized by [P(C6H5)3]12Cl6 ligands. At low temperature, the thermal motion of the clusters as well as the thermal drift of the STM are reduced, so that measurements can be performed reproducibly with highest spatial and spectroscopic resolution. At 7 K we imaged for the first time the actual arrangement of the C6H5 rings of the ligand molecules. Spectroscopic data acquired from well defined locations within a cluster reveal Energy‐Level Splitting which can be attributed to the Au55 core. The individual Energy Levels are deduced by using a Monte Carlo simulation of electronic transport through a double tunnel junction. Experimental results are compared with those obtained by density‐functional tight‐binding calculations.
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Energy‐Level Splitting of Ligand‐Stabilized Au55 Clusters Observed by Low‐Temperature Scanning Tunneling Spectroscopy
AIP Conference Proceedings, 2003Co-Authors: Huijing Zhang, Holger Grzeschik, Pranab Kumar Sarkar, Michael Springborg, Uwe HartmannAbstract:Low‐temperature ultrahigh‐vacuum (UHV) scanning tunneling microscopy (STM) and spectroscopy (STS) were employed to analyze the electronic structure of Au55 clusters stabilized by [P(C6H5)3]12Cl6 ligands. At low temperature, the thermal motion of the clusters as well as the thermal drift of the STM are reduced, so that measurements can be performed reproducibly with highest spatial and spectroscopic resolution. At 7 K we imaged for the first time the actual arrangement of the C6H5 rings of the ligand molecules. Spectroscopic data acquired from well defined locations within a cluster reveal Energy‐Level Splitting which can be attributed to the Au55 core. The individual Energy Levels are deduced by using a Monte Carlo simulation of electronic transport through a double tunnel junction. Experimental results are compared with those obtained by density‐functional tight‐binding calculations.
James P. Kneller - One of the best experts on this subject based on the ideXlab platform.
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Stimulated neutrino transformation with sinusoidal density profiles
Journal of Physics G: Nuclear and Particle Physics, 2013Co-Authors: James P. Kneller, Gail C. Mclaughlin, Kelly M. PattonAbstract:Large amplitude oscillations between the states of a quantum system can be stimulated by sinusoidal external potentials with frequencies that are similar to the Energy Level Splitting of the states or a fraction thereof. Situations where the applied frequency is equal to an integer fraction of the Energy Level Splittings are known as parametric resonances. We investigate this effect for neutrinos both analytically and numerically for the case of arbitrary numbers of neutrino flavors. We look for environments where the effect may be observed and find that supernovae are the one realistic possibility due to the necessity of both large densities and large amplitude fluctuations. In conclusion, the comparison of numerical and analytical results of neutrino propagation through a model supernova reveals that it is possible to predict the locations and strengths of the stimulated transitions that occur.
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Stimulated Neutrino Transformation in Supernovae
arXiv: High Energy Physics - Phenomenology, 2012Co-Authors: James P. Kneller, Gail C. Mclaughlin, Kelly M. PattonAbstract:Large amplitude oscillations between states of a quantum system can be stimulated by sinusoidal external potentials with frequencies that are equal to the Energy Level Splitting of the states or a fraction thereof. We investigate this effect for neutrino oscillations both analytically and numerically finding a simple expression for amplitude and wavelength of the transitions as a function of the density, the amplitude and wavenumber of the fluctuation, and the matter mixing matrix elements. We apply our findings to the supernova environment and find that it is possible to predict stimulated transitions that occur due to sinusoidal perturbations in the density.