350 citations · 2k across the 44 of their papers we have counts for
32 papers · 1 filter
Between Mott and cluster Mott: spin-orbit entangled dimer singlets in BaCeRuO
L. Pätzold, A. Sandberg, H. Schilling +8
The hexagonal 4d ruthenates Ba3MRu2O9 host structural dimers and exhibit a delicate balance of competing interactions. Hund's coupling, trigonal crystal-field splitting, and hoppin…
Magnetic-field-induced critical dynamics in magnetoelectric TbPO
Christoph P. Grams, Markus Grüninger, Joachim Hemberger
We report on the magnetoelectric dynamics in the linear magnetoelectric antiferromagnet TbPO studied by broadband dielectric spectroscopy. For the phase transition into the mag…
Spin-orbit coupling in a half-filled shell: the case of KReCl
P. Warzanowski, M. Magnaterra, G. Schlicht +9
The half-filled shell of the configuration usually, in LS coupling, hosts a S = 3/2 ground state with quenched orbital moment. This state is not Jahn-Teller act…
Quasimolecular =3/2 moments in the cluster Mott insulator GaTaSe
M. Magnaterra, J. Attig, L. Peterlini +8
Quasimolecular orbitals in cluster Mott insulators provide a route to tailor exchange interactions, which may yield novel quantum phases of matter. We demonstrate the cluster Mott…
Spin-orbit coupling and crystal-field splitting in Ti-doped Ca2RuO4 studied by ellipsometry
I. Vergara, M. Magnaterra, J. Attig +5
In Ca2RuO4, the competition of spin-orbit coupling and tetragonal crystal field splitting has been discussed controversially for many years. The orbital occupation dep…
Magnetoelectric coupling in the mixed erythrosiderite [(NH)K][FeCl(HO)]
Daniel Brüning, Tobias Fröhlich, Malte Langenbach +7
We present a study of the dielectric, structural, and magnetic properties of the multiferroic or linear magnetoelectric substitution series [(NH)K][FeCl(H$_…
Multiple Spin-Orbit Excitons and the Electronic Structure of -RuCl
P. Warzanowski, N. Borgwardt, K. Hopfer +7
The honeycomb compound -RuCl is widely discussed as a proximate Kitaev spin-liquid material. This scenario builds on spin-orbit entangled moments arising for a $t_…
High-Field Quantum Disordered State in -RuCl3: Spin Flips, Bound States, and a Multi-Particle Continuum
A. Sahasrabudhe, D. A. S. Kaib, S. Reschke +15
Layered -RuCl3 has been discussed as a proximate Kitaev spin liquid compound. Raman and THz spectroscopy of magnetic excitations confirm that the low-temperature antiferromagnet…
Resonant inelastic x-ray incarnation of Young's double-slit experiment
A. Revelli, M. Moretti Sala, G. Monaco +12
Young's archetypal double-slit experiment forms the basis for modern diffraction techniques: the elastic scattering of waves yields an interference pattern that captures the real-s…
Spin-orbit entangled j=1/2 moments in BaCeIrO -- a frustrated fcc quantum magnet
A. Revelli, C. C. Loo, D. Kiese +16
We establish the double perovskite BaCeIrO as a nearly ideal model system for j=1/2 moments, with resonant inelastic x-ray scattering indicating a deviation of less than 1%…
Low temperature enhancement of ferromagnetic Kitaev correlations in α-RuCl3
Andreas Koitzsch, Eric Mueller, Martin Knupfer +7
Kitaev-type interactions between neighbouring magnetic moments emerge in the honeycomb material -RuCl3. It is debated however whether these Kitaev interactions are ferromagnetic…
Phase separation in the non-equilibrium Verwey transition in magnetite
Francesco Randi, Ignacio Vergara, Fabio Novelli +9
We present equilibrium and out-of-equilibrium studies of the Verwey transition in magnetite. In the equilibrium optical conductivity, we find a step-like change at the phase transi…
Infrared-active phonon modes in monoclinic multiferroic MnWO4
T. Möller, P. Becker, L. Bohaty +2
We report on polarized infrared reflectivity measurements of multiferroic, monoclinic MnWO4 between 10K and 295K. The full dielectric tensor and the frequency dependence of the ori…
Witnessing the formation and relaxation of massive quasi-particles in a strongly correlated electron system
Fabio Novelli, Giulio De Filippis, Vittorio Cataudella +17
The non-equilibrium semiconductors physics is based on the paradigm that different degrees of freedom interact on different timescales. In this context the photo-excitation is ofte…
Temperature-dependent optical conductivity of layered LaSrFeO_4
J. Reul, L. Fels, N. Qureshi +3
Compounds with intermediate-size transition metals such as Fe or Mn are close to the transition between charge-transfer systems and Mott-Hubbard systems. We study the optical condu…
Probing orbital fluctuations in RVO3 (R = Y, Gd, or Ce) by ellipsometry
J. Reul, A. A. Nugroho, T. T. M. Palstra +1
We study optical excitations across the Mott gap in the multi-orbital Mott-Hubbard insulators RVO3. The multi-peak structure observed in the optical conductivity can be described c…
Hubbard exciton revealed by time-domain optical spectroscopy
Fabio Novelli, Daniele Fausti, Julia Reul +6
We use broadband ultra-fast pump-probe spectroscopy in the visible range to study the lowest excitations across the Mott-Hubbard gap in the orbitally ordered insulator YVO3. Separa…
CaCrO3: an anomalous antiferromagnetic metallic oxide
A. C. Komarek, S. V. Streltsov, M. Isobe +13
Combining infrared reflectivity, transport, susceptibility and several diffraction techniques, we find compelling evidence that CaCrO3 is a rare case of a metallic and antiferromag…
Collective orbital excitations in orbitally ordered YVO3 and HoVO3
E. Benckiser, R. Rückamp, T. Möller +6
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 feat…
Mott-Hubbard versus charge-transfer behavior in LaSrMnO4 studied via optical conductivity
A. Gössling, M. W. Haverkort, M. Benomar +6
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 g…
Optical study of orbital excitations in transition-metal oxides
R. Rückamp, E. Benckiser, M. W. Haverkort +13
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…
Charge order induced sharp Raman peak in Sr_14Cu_24O_41
K. P. Schmidt, C. Knetter, M. Grüninger +1
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,…
Evidence for a Low-Spin to Intermediate-Spin State Transition in LaCoO3
C. Zobel, M. Kriener, D. Bruns +5
We present measurements of the magnetic susceptibility and of the thermal expansion of a LaCoO single crystal. Both quantities show a strongly anomalous temperature dependence.…
Cyclic Spin Exchange in Cuprate Spin Ladders
Tamara S. Nunner, Philipp Brune, Thilo Kopp +2
We investigate the influence of a cyclic spin exchange J_{cyc} on the one- and two-triplet excitations of an undoped two-leg S=1/2 ladder, using the density matrix renormalization…