We present an electron spin resonance (ESR) study of a single-crystalline spin chain system CuSe2O5 in the frequency range between 9 and 430 GHz. In a wide temperature range above the Neel temperature T-N = 17 K we observe a strong and anisotropic frequenc ...
dc and ac magnetization measurements were performed on single-crystal Cu2OSeO3 under magnetic field (H) and hydrostatic pressure (P) conditions. Increasing H shifts the ferrimagnetic transition observed at T-C similar to 60 K to a higher-temperature region ...
The anharmonic response of charge-density wave (CDW) order to strong laser-pulse perturbations in 1T-TaS2 and TbTe3 is investigated by means of multiple-pump-pulse time-resolved femtosecond optical spectroscopy. We observe remarkable anharmonic effects hit ...
The transient optical conductivity of photoexcited 1T-TaS2 is determined over a three-order-of-magnitude frequency range. Prompt collapse and recovery of the Mott gap is observed. However, we find important differences between this transient metallic state ...
We report on magnetization and specific heat measurements on single-crystalline CuTe2O5. The experimental data are directly compared to theoretical results for two different spin structures, namely an alternating spin-chain and a two-dimensional (2D) coupl ...
Phonon frequency and linewidth as well as quasielastic scattering due to spin energy fluctuations are used to evaluate the evolution of spin correlations in a spin chain system with considerable interchain coupling. In the compound CuSe2O5 these interactio ...
Multiple charge density wave (CDW) phases in 2H-TaSe2 are investigated by high-resolution synchrotron x-ray diffraction. In a narrow temperature range immediately above the commensurate CDW transition, we observe a multi-q superstructure with coexisting co ...
The recently discovered topological insulators exhibit topologically protected metallic surface states which are interesting from the fundamental point of view and could be useful for various applications if an appropriate electronic gating can be realized ...
Dichalcogenides with the common formula MX2 are layered materials with electrical properties that range from semiconducting to superconducting. Here, we describe optimal imaging conditions for the optical detection of ultrathin, two-dimensional dichalcogen ...
The magnetic susceptibility and magnetization of high-quality single-crystal beta-TeVO4 are reported. We show that this compound, made of weakly coupled infinite chains of VO5 pyramids sharing corners, behaves as an S = 1/2 one-dimensional Heisenberg antif ...
We use time- and angle-resolved photoemission spectroscopy with sub-30-fs extreme-ultraviolet pulses to map the time- and momentum-dependent electronic structure of photoexcited 1T-TaS2. This compound is a two-dimensional Mott insulator with charge-density ...
Resonant magnetic x-ray scattering near the vanadium L-2,L-3-absorption edges has been used to investigate the low temperature magnetic structure of high quality BaVS3 single crystals. Below T-N = 31 K, the strong resonance revealed a triple-incommensurate ...
We investigate the dispersion of the charge carrier plasmon in the three prototypical charge-density wave bearing transition-metal dichalcogenides 2H-TaSe2, 2H-TaS2, and 2H-NbSe2 employing electron energy-loss spectroscopy. For all three compounds the plas ...
A detailed zero-and transverse-field muon spin rotation investigation of magnetism and the magnetoelectric coupling in Cu2OSeO3 is reported. An internal magnetic field B-int(T = 0) = 85.37(25) mT was found, in agreement with a ferrimagnetic state below T-c ...
A new copper selenite chloride Cu-5(SeO3)(4)Cl-2 has been prepared by chemical vapor transport reactions. Its crystal structure was determined by single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P2(1)/c with t ...
We present a thorough Se-77 nuclear-magnetic-resonance (NMR) study of a single crystal of the magnetoelectric compound Cu2OSeO3. The temperature dependence of the local electronic moments extracted from the NMR data is fully consistent with a magnetic phas ...
The low-temperature magnetic phase diagram of the multiferroic system FeTe2O5Br down to 300 mK and up to 9 T is presented. Short-range magnetic correlations within the crystal layers start to develop already at similar to 50 K, i.e., far above T-N1 similar ...
sublattices ferrimagnet Cu2OSeO3 with a cubic symmetry and a linear magnetoelectric effect. There is no spectroscopic evidence for structural lattice distortions below T-C=60 K, which are expected due to magnetoelectric coupling. Using symmetry arguments w ...
Using friction force microscopy, we compared the nanoscale frictional characteristics of atomically thin sheets of graphene, molybdenum disulfide (MoS2), niobium diselenide, and hexagonal boron nitride exfoliated onto a weakly adherent substrate (silicon o ...
American Association for the Advancement of Science2010
The resonance properties of a new Cu2OSeO3 ferrimagnet have been investigated in a wide range of frequencies (17-142 GHz) at liquid helium temperature. The resonance data were used to plot the frequency-field curve of the ferromagnetic spectrum described i ...