M. Knupfer

Publication List Details

Period

1996 - 2008

Number

86

Co-Authors

Bulk and surface switching in Mn-Fe-based Prussian Blue Analogues (2008)

Lummen, T. T. A., Gengler, R. Y. N., Rudolf, P., Lusitani, F., Vertelman, E. J. M., Van Koningsbruggen, P. J., ...

Many Prussian Blue Analogues are known to show a thermally induced phase transition close to room temperature and a reversible, photo-induced phase transition at low temperatures. This work reports...

Momentum dependence of the superconducting gap in Ba$_{1-x}$K$_{x}$Fe$_2$As$_2$ (2008)

Evtushinsky, D. V., Inosov, D. S., Zabolotnyy, V. B., Koitzsch, A., Knupfer, M., Buchner, B., ...

The precise momentum dependence of the superconducting gap in the iron-arsenide superconductor with Tc = 32K (BKFA) was determined from angle-resolved photoemission spectroscopy (ARPES) via fitting...

Unexpected Fermi surface topology in the new pnictide superconductor (2008)

Zabolotnyy, V. B., Inosov, D. S., Evtushinsky, D. V., Koitzsch, A., Kordyuk, A. A., Park, J. T., ...

Discovery of superconductivity in pnictides filled in the gap between the critical transition temperatures of conventional and unconventional superconductors [1-10]. According to first angle-resolved...

On the electronic structure of electron doped LaOFeAs as seen by X-ray absorption spectroscopy (2008)

Kroll, T., Bonhommeau, S., Kachel, T., Duerr, H. A., Werner, J., Behr, G., ...

We investigated the recently found superconductor LaO_{1-x}F_xFeAs by X-ray absorption spectroscopy (XAS). From a comparison of the O K-edge with LDA calculations we find good agreement and are able...

Pauli limiting behavior and enhanced upper critical fields of an As deficient LaO_0.9F_0.1FeAs_(1-\delta) superconductor probed by high external fields (2008)

Fuchs, G., Kozlova, N., Behr, G., Koehler, A., Werner, J., ...

We report upper critical field B_c2(T) data for disordered (As deficient) LaO_0.9F_0.1FeAs_(1-delta) in a wide temperature and field range up to 47 T. Due to the large initial slope of dBc2/dT about...

Electronic structure of LaO_{1-x}F_xFeAs from Photoemission Spectroscopy (2008)

Koitzsch, A., Inosov, D., Fink, J., Knupfer, M., Eschrig, H., Borisenko, S. V., ...

We have investigated the electronic structure of LaO_{1-x}F_xFeAs (x = 0; 0.1; 0.2) by angle-integrated photoemission spectroscopy. The valence band consists of a low energy peak at E = -0.25 eV and...

An optical study of the La0.9F0.1FeAs superconductor and a first empirical estimate of its weak coupling regime (2008)

Grobosch, M., Koepernik, K., Behr, G., Koehler, A., Werner, J., ...

We have studied the reflectance of the recently discovered superconductor LaO0.9F0.1FeAs in a wide energy range from the far infrared to the visible regime. We report on the observation of infrared...

Excitation energy map of the high-energy dispersion anomalies in cuprates (2008)

Inosov, D. S., Schuster, R., Kordyuk, A. A., Fink, J., Borisenko, S. V., Zabolotnyy, V. B., ...

The anomalous high-energy dispersion of the conductance band in the high-Tc superconductor Pb-Bi2212 has been extensively mapped by angle-resolved photoemission (ARPES) as a function of excitation...

Electron-Electron Correlation in Graphite: A Combined Angle-Resolved Photoemission and First-Principles Study (2008)

Grüneis, A., Attaccalite, C., Pichler, T., Zabolotnyy, V., Shiozawa, H., Molodtsov, S.L., ...

The full three-dimensional dispersion of the π bands, Fermi velocities, and effective masses are measured with angle-resolved photoemission spectroscopy and compared to first-principles...

Bulk and Surface Switching in Mn-Fe-Based Prussian Blue Analogues (2008)

Lummen, T.T.A., Gengler, R.Y.N., Rudolf, P., Lusitani, F., Vertelman, E.J.M., Koningsbruggen, P.J. Van, ...

Many Prussian blue analogues are known to show a thermally induced phase transition close to room temperature and a reversible, photoinduced phase transition at low temperatures. This work reports on...

Bulk and Surface Switching in Mn-Fe-Based Prussian Blue Analogues (2008)

Lummen, T.T.A., Gengler, R.Y.N., Rudolf, P., Lusitani, F., Vertelman, E.J.M., Koningsbruggen, P.J. Van, ...

Many Prussian blue analogues are known to show a thermally induced phase transition close to room temperature and a reversible, photoinduced phase transition at low temperatures. This work reports on...

Momentum and excitation energy dependence of the "waterfalls" in cuprates (2007)

Inosov, D. S., Fink, J., Kordyuk, A. A., Borisenko, S. V., Zabolotnyy, V. B., Schuster, R., ...

Using high-resolution angle-resolved photoemission spectroscopy we have studied the momentum and photon energy dependence of the anomalous high-energy dispersion, termed "waterfalls", between the...

"Waterfalls" phenomenon in superconducting cuprates (2007)

Inosov, D. S., Kordyuk, A. A., Borisenko, S. V., Zabolotnyy, V. B., Fink, J., Knupfer, M., ...

We show that the "waterfalls", as reported in recent ARPES studies on HTSC, can neither be described as a part of a self-consistent quasiparticle spectrum nor represent a new physical phenomena,...

Manifestation of the magnetic resonance mode in the nodal quasiparticle lifetime of the superconducting cuprates (2006)

Kordyuk, A. A., Borisenko, S. V., Koitzsch, A., Fink, J., Knupfer, M., Buchner, B., ...

Studying the nodal quasiparticles in superconducting cuprates by photoemission with highly improved momentum resolution, we show that a new "kink" feature in the scattering rate is a key to uncover...

Constituents of the Quasiparticle Spectrum Along the Nodal Direction of High-Tc Cuprates (2006)

Kordyuk, A. A., Borisenko, S. V., Zabolotnyy, V. B., Geck, J., Knupfer, M., Fink, J., ...

Applying the Kramers-Kronig consistent procedure, developed earlier, we investigate in detail the formation of the quasiparticle spectrum along the nodal direction of high-Tc cuprates. The heavily...

Effect of Zn and Ni impurities on the quasiparticle renormalization of superconducting Bi-2212 (2006)

Zabolotnyy, V. B., Borisenko, S. V., Kordyuk, A. A., Fink, J., Geck, J., Koitzsch, A., ...

The Cu substitution by Zn and Ni impurities and its influence on the mass renormalization effects in angle-resolved photoelectron spectra (ARPES) of Bi2Sr2CaCu2O8-delta is addressed. We show that the...

Unadulterated spectral function of low-energy quasiparticles in Bi2Sr2CaCu2O8+δ (2006)

Evtushinsky, D. V., Kordyuk, A. A., Borisenko, S. V., Zabolotnyy, V. B., Knupfer, M., Fink, J., ...

Fitting the momentum distribution photoemission spectra to the Voigt profile appears to be a robust procedure to purify the interaction effects from the experimental resolution. In application to...

Constituents of the Quasiparticle Spectrum Along the Nodal Direction of High-Tc Cuprates (2006)

Kordyuk, A. A., Borisenko, S. V., Zabolotnyy, V. B., Geck, J., Knupfer, M., Fink, J., ...

Applying the Kramers-Kronig consistent procedure, developed earlier, we investigate in detail the formation of the quasiparticle spectrum along the nodal direction of high-Tc cuprates. The heavily...

Circular dichroism and bilayer splitting in the normal state of underdoped (Pb,Bi)2Sr2(CaxY1-x)Cu2O8+delta and overdoped (Pb,Bi)2Sr2Ca1Cu2O8+delta (2004)

Borisenko, S.V., Kordyuk, A.A., Legner, S., Kim, T.K., Knupfer, M., Schneider, C.M., ...

We report an ARPES investigation of the circular dichroism in the first Brillouin zone (BZ) of under- and overdoped Pb-Bi2212 samples. We show that the dichroism has opposite signs for bonding and...

Manifestation of the Magnetic Resonance Mode in the Nodal Quasiparticle Lifetime of the Superconducting Cuprates (2004)

Kordyuk, A. A., Borisenko, S. V., Koitzsch, A., Fink, J., Knupfer, M., Büchner, B., ...

Studying the nodal quasiparticles in superconducting cuprates by photoemission with highly improved momentum resolution, we show that a new "kink" feature in the scattering rate is a key to uncover...

Origin of the shadow Fermi surface in Bi-based cuprates (2004)

Koitzsch, A., Borisenko, S. V., Kordyuk, A. A., Kim, T. K., Knupfer, M., Fink, J., ...

We used angle-resolved photoemission spectroscopy to study the shadow Fermi surface in one layer Bi2Sr1.6La0.4CuO6+delta and two layer (Bi,Pb)(2)Sr2CaCu2O8+delta. We find the shadow band to have the...

Origin of the shadow Fermi surface in Bi-based cuprates. (2004)

Koitzsch, A., Borisenko, S.V., Kordyuk, A.A., Kim, T.K., Knupfer, M., Fink, J., ...

We used angle-resolved photoemission spectroscopy to study the shadow Fermi surface in one layer Bi2Sr1.6La0.4CuO6 + delta and two layer (Bi,Pb)2Sr2CaCu2O8 + delta. We find the shadow band to have...

XAS spectra of Ce2[MnN3] at the Ce-M4,5, Ce-L3, MnL2.3 and N-K thresholds (2002)

Niewa, R., Hu, Z., Grazioli, C., Rößler, U., Golden, M. S., Knupfer, M., ...

The X-ray absorption spectroscopy at the Ce-M-4.5, Ce-L-3, Mn- L-2,L-3 and N-K thresholds was used to study the electronic and magnetic structure of the recently obtained Ce-2[MnN3]. Manganese is...

Proof for trivalent Sc ions in Sc2@C84 from high-energy spectroscopy (2000)

Pichler, T., Grazioli, C., Legner, S., Knupfer, M., Golden, M.S., Fink, J., ...

The electronic structure and the valency of the Sc ions in the endohedral dimetallofullerene Sc 2 @C 84 with D 2d symmetry are probed using high-energy spectroscopy. Comparison of the Sc 2p ! 3d...

Proof for trivalent Sc ions in Sc2@C84 from high-energy spectroscopy (2000)

Pichler, T., Hu, Z., Grazioli, C., Legner, S., Knupfer, M., Golden, M.S., ...

The electronic structure and the valency of the Sc ions in the endohedral dimetallofullerene Sc2@C84 with D2d symmetry are probed using high-energy spectroscopy. Comparison of the Sc 2p→3d...

Diameter grouping in bulk samples of single-walled carbon nanotubes from optical absorption spectroscopy (1999)

Golden, M. S., Fink, J., Dunsch, L., Reibold, M., Knupfer, M., ...

The influence of the synthesis parameters on the mean characteristics of single-wall carbon nanotubes in soot produced by the laser vaporization of graphite has been analyzed using optical absorption...