858 research outputs found

    Testing the validity of THz reflection spectra by dispersion relations

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    Complex response function obtained in reflection spectroscopy at terahertz range is examined with algorithms based on dispersion relations for integer powers of complex reflection coefficient, which emerge as a powerful and yet uncommon tools in examining the consistency of the spectroscopic data. It is shown that these algorithms can be used in particular for checking the success of correction of the spectra by the methods of Vartiainen et al [1] and Lucarini et al [2] to remove the negative misplacement error in the terahertz time-domain spectroscopy.Comment: 17 pages, 4 figure

    Charge ordering and chemical potential shift in La2−x_{2-x}Srx_xNiO4_4 studied by photoemission spectroscopy

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    We have studied the chemical potential shift in La2−x_{2-x}Srx_xNiO4_4 and the charge ordering transition in La1.67_{1.67}Sr0.33_{0.33}NiO4_4 by photoemission spectroscopy. The result shows a large (∼\sim 1 eV/hole) downward shift of the chemical potential with hole doping in the high-doping regime (δ≳\delta \gtrsim 0.33) while the shift is suppressed in the low-doping regime (δ≲\delta \lesssim 0.33). This suppression is attributed to a segregation of doped holes on a microscopic scale when the hole concentration is lower than δ≃1/3\delta \simeq 1/3. In the δ=1/3\delta = 1/3 sample, the photoemission intensity at the chemical potential vanishes below the charge ordering transition temperature TCO=T_{\rm CO}= 240 K.Comment: 5 pages, 4 figure

    Survival Wolio Language in Adulthood in Baubau City: Sociolinguistic Study

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    The article is the result of a study that discusses the survival of Wolio language in adolescence in Baubau City. The focus of this study is adults aged between 17-20 years. As for the domain of the question is the family, association, education, government, transactions, neighbors, religion, culture, art. In this research, the approach used is the sociolinguistic approach. In this case, the approach (approach) of sociology, namely the study of language in the social context, which is studied is the behavior of groups rather than individual behavior. In analyzing the data is done by calculating the percentage following the calculation pattern, that is the calculation based on the number of incoming answers) The results are found Wolio language Based on the analysis shows that in the adult category the tendency of the use of Wolio language has been in the category even though on the defense side still last

    Effect of Stripes on Electronic States in Underdoped La_{2-x}Sr_xCuO_4

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    We investigate the electronic states of underdoped La_{2-x}Sr_xCuO_4 (LSCO) by using a microscopic model, i.e., t-t'-t''-J model, containing vertical charge stripes. The numerically exact diagonalization calculation on small clusters shows the consistent explanation of the physical properties in the angle-resolved photoemission, neutron magnetic scattering and optical conductivity experiments such as the antiphase domain and quasi-one-dimensional charge transport. The pair correlation function of the d-channel is suppressed by the stripes. These results demonstrate a crucial role of the stripes in LSCOComment: 4 pages, 4 EPS figures, revised version, to appear in Phys. Rev. Lett. Vol.82, No.25, 199

    Diffusion and activation of n-type dopants in germanium

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    The diffusion and activation of nn-type impurities (P and As) implanted into pp-type Ge(100) substrates were examined under various dose and annealing conditions. The secondary ion mass spectrometry profiles of chemical concentrations indicated the existence of a sufficiently high number of impurities with increasing implanted doses. However, spreading resistance probe profiles of electrical concentrations showed electrical concentration saturation in spite of increasing doses and indicated poor activation of As relative to P in Ge. The relationships between the chemical and electrical concentrations of P in Ge and Si were calculated, taking into account the effect of incomplete ionization. The results indicated that the activation of P was almost the same in Ge and Si. The activation ratios obtained experimentally were similar to the calculated values, implying insufficient degeneration of Ge. The profiles of P in Ge substrates with and without damage generated by Ge ion implantation were compared, and it was clarified that the damage that may compensate the activated nn-type dopants has no relationship with the activation of P in Ge.Comment: 6 pages, 4 figure
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