Collective orbital excitations in orbitally ordered YVO3 and HoVO3 (2008)
Benckiser, E., Rückamp, R., Möller, T., Taetz, T., Möller, A., Nugroho, A. A., ...
We study orbital excitations in the optical absorption spectra of YVO3 and HoVO3. We focus on an orbital absorption band observed at 0.4 eV for polarization E parallel c. This feature is only...
Collective orbital excitations in orbitally ordered YVO3 and HoVO3 (2008)
Benckiser, E., Rückamp, R., Möller, T., Taetz, T., Möller, A., Nugroho, A.A., ...
We study orbital excitations in the optical absorption spectra of YVO3 and HoVO3.We focus on an orbital absorption band observed at 0.4 eV for polarization E || c. This feature is only observed in...
Mott-Hubbard versus charge-transfer behavior in LaSrMnO4 studied via optical conductivity (2007)
Gössling, A., Haverkort, M. W., Benomar, M., Wu, H., Senff, D., Möller, T., ...
Using spectroscopic ellipsometry, we study the optical conductivity sigma(omega) of insulating LaSrMnO4 in the energy range of 0.75-5.8 eV from 15 to 330 K. The layered structure gives rise to a...
Mott-Hubbard exciton in the optical conductivity of YTiO3 and SmTiO3 (2006)
Gössling, A., Schmitz, R., Roth, H., Haverkort, M. W., Lorenz, T., Mydosh, J. A., ...
In the Mott-Hubbard insulators YTiO3 and SmTiO3 we study optical excitations from the lower to the upper Hubbard band, d^1d^1 -> d^0d^2. The multi-peak structure observed in the optical conductivity...
The fate of orbitons coupled to phonons (2006)
Schmidt, K. P., Grüninger, M., Uhrig, G. S.
The key feature of an orbital wave or orbiton is a significant dispersion, which arises from exchange interactions between orbitals on distinct sites. We study the effect of a coupling between...
Raman scattering in the Mott insulators LaTiO3 and YTiO3: Evidence for orbital excitations (2006)
Ulrich, C., Gössling, A., Grüninger, M., Guennou, M., Roth, H., Cwik, M., ...
Raman scattering is used to observe pronounced electronic excitations around 230 meV-well above the two-phonon range-in the Mott insulators LaTiO3 and YTiO3. Based on the temperature, polarization,...
Phonon modes of monoclinic BiB3O6 (2005)
Gössling, A., Möller, T., Becker, P., Bohatý, L., Grüninger, M.
We present a detailed study of the phonon modes of the monoclinic compound BiB3O6 based on polarized reflectivity measurements on single crystals. The spectra are analysed by means of a generalized...
Optical study of orbital excitations in transition-metal oxides (2005)
Rückamp, R., Benckiser, E., Haverkort, M. W., Roth, H., Lorenz, T., Freimuth, A., ...
The orbital excitations of a series of transition-metal compounds are studied by means of optical spectroscopy. Our aim was to identify signatures of collective orbital excitations by comparison with...
Zero-field incommensurate spin-Peierls phase with interchain frustration in TiOCl (2005)
Rückamp, R., Baier, J., Kriener, M., Haverkort, M. W., Lorenz, T., Uhrig, G. S., ...
We report on the magnetic, thermodynamic and optical properties of the quasi-one-dimensional quantum antiferromagnets TiOCl and TiOBr, which have been discussed as spin-Peierls compounds. The...
Orbital excitations in titanates (2005)
Ulrich, C., Gössling, A., Grüninger, M., Guennou, M., Roth, H., Cwik, M., ...
Raman scattering is used to observe pronounced electronic excitations around 230 meV - well above the two-phonon range - in the Mott insulators LaTiO$_3$ and YTiO$_3$. Based on the temperature,...
Magnetic Excitations in Bilayer High-Temperature Superconductors with Stripe Correlations (2005)
Uhrig, G. S., Schmidt, K. P., Grüninger, M.
The universal behaviour of the magnetic excitations in high-temperature superconductors is described in a model with static stripes retaining only the localized spin degrees of freedom. The stripes...
Magnetic excitations in the stripe phase of high-T_c superconductors (2004)
Uhrig, G. S., Schmidt, K. P., Grüninger, M.
The magnetic excitations in the stripe phase of high-T_c superconductors are investigated in a model of spin ladders which are effectively coupled via charged stripes. Starting from the effective...
Unifying Magnons and Triplons in Stripe-Ordered Cuprate Superconductors (2004)
Uhrig, G. S., Schmidt, K. P., Grüninger, M.
Based on a two-dimensional model of coupled two-leg spin ladders, we derive a unified picture of recent neutron scattering data of stripe-ordered La_(15/8)Ba_(1/8)CuO_4, namely of the low-energy...
Evidence for a large magnetic heat current in insulating layered cuprates (2003)
Brück, E.H., Hofmann, M., Lorenz, T., Berggold, K., Grüninger, M., Freimuth, A.
Charge order induced sharp Raman peak in Sr_14Cu_24O_41 (2002)
Schmidt, K. P., Knetter, C., Grüninger, M., Uhrig, G. S.
In the two-leg S=1/2 ladders of Sr_14Cu_24O_41 a modulation of the exchange coupling arises from the charge order within the other structural element, the CuO_2 chains. In general, breaking...
Fractional and Integer Excitations in Quantum Antiferromagnetic Spin 1/2 Ladders (2001)
Knetter, C., Schmidt, K. P., Grüninger, M., Uhrig, G. S.
Spectral densities are computed in unprecedented detail for quantum antiferromagnetic spin 1/2 two-leg ladders. These results were obtained due to a major methodical advance achieved by optimally...
Kataev, V., Grüninger, M., Ammerahl, U., Büchner, B., Freimuth, A., ...
Electron spin resonance data of Cu^{2+} ions in La_{14-x}Ca_{x}Cu_{24}O_{41} crystals (x=9,11,12) reveal a very large width of the resonance line in the paramagnetic state. This signals an unusually...
Observation of out-of-phase bilayer plasmons in $YBa_{2}Cu_{3}O_{7-delta}$ (1999)
Tsvetkov, A. A., Marel, D. Van Der, Grüninger, M., Erb, A.
Published in: Phys. Rev. Lett. 84 (2000) 1575 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: The temperature dependence of the c-axis optical conductivity...
Charged Magnons in $alpha'- NaV_{2}O_{5}$ (1998)
Jegoudez, J., Palstra, T. T. M., Presura, C., Grüninger, M., Marel, D. Van Der, Damascelli, A.
Published in: Phys. Rev. Lett. 81 (1998) 918 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: We investigated the temperature-dependent optical conductivity of...
Direct Two-Magnon Optical Absorption in α'-NaV2O5: “Charged” Magnons (1998)
Damascelli, A., Marel, D. Van Der, Grüninger, M., Presura, C., Palstra, T.T.M., Jegoudez, J., ...
We investigate the temperature-dependent optical conductivity of α'-NaV2O5 in the energy range 4 meV–4 eV. The intensities and the polarization dependence of the detected electronic excitations...
Spin-Waves in the Mid-Infrared Spectrum of Antiferromagnetic YBa$_2$Cu$_3$O$_{6.0}$ (1995)
Grüninger, M., Münzel, J., Gaymann, A., Zibold, A., Geserich, H. P., Kopp, T.
The mid-infrared spin-wave spectrum of antiferromagnetic YBa$_2$Cu$_3$O$_{6.0}$\ was determined by infrared transmission and reflection measurements ($\bbox{k} \!\! \parallel $c) at $T\!=\!10\!$~K.\@...
Rordorf-Adam, C, Serban, D, Pataki, A, Grüninger, M
The concentration of immunoglobulins, anti-ssDNA, anti-dsDNA, anti-TNP antibodies, IgM rheumatoid factor, C3, immune complexes and serum amyloid P component (SAP), in the serum were measured in 68...