460 citations · 2.5k across the 63 of their papers we have counts for
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Thermally populated versus field-induced triplon bound states in the Shastry-Sutherland lattice SrCu(BO)
Dirk Wulferding, Youngsu Choi, Seungyeol Lee +6
The Shastry-Sutherland compound SrCu(BO) constituting orthogonally coupled dimers harbors a singlet ground state. The confluence of strong interdimer interaction…
Non-Abelian statistics in light scattering processes across interacting Haldane chains
Vladimir Gnezdilov, Vladimir Kurnosov, Yurii Pashkevich +6
The Haldane state is constructed from a product of local singlet dimers in the bulk and topological states at the edges of a chain. It is a fundamental representative of topo…
Effect of topology on quasi-particle interactions in the Weyl semimetal WP
Dirk Wulferding, Peter Lemmens, Florian Büscher +3
We compare two crystallographic phases of the low-dimensional WP to better understand features of electron-electron and electron-phonon interactions in topological systems. The…
Magnon bound states vs. anyonic Majorana excitations in the Kitaev honeycomb magnet -RuCl
Dirk Wulferding, Youngsu Choi, Seung-Hwan Do +5
The pure Kitaev honeycomb model harbors a quantum spin liquid in zero magnetic fields, while applying finite magnetic fields induces a topological spin liquid with non-Abelian anyo…
Systematic Raman study of optical phonons in BaCuO ( = Y, Dy, Gd, Sm, Nd): Antiferromagnetic coupling strength versus lattice parameters
Silvia Müllner, Wayne Crump, Dirk Wulferding +4
We present a systematic study of the interplay between lattice parameters and the energy of the optical phonons as well as the antiferromagnetic coupling strength, , in the high…
Soft tilt and rotational modes in the hybrid improper ferroelectric CaMnO
A. Glamazda, D. Wulferding, P. Lemmens +3
Raman spectroscopy is employed to probe directly the soft rotation and tilting modes, which are two primary order parameters predicted in the hybrid improper ferroelectric material…
Quantum criticality in the coupled two-leg spin ladder Ba2CuTeO6
A. Glamazda, Y. S. Choi, S. -H. Do +8
We report on zero-field muon spin rotation, electron spin resonance and polarized Raman scattering measurements of the coupled quantum spin ladder Ba2CuTeO6. Zero-field muon spin r…
Relation between Kitaev magnetism and structure in -RuCl
A. Glamazda, P. Lemmens, S. -H. Do +2
Raman scattering has been employed to investigate lattice and magnetic excitations of the honeycomb Kitaev material -RuCl and its Heisenberg counterpart CrCl. Our phonon…
Raman spectroscopic signature of fractionalized excitations in the harmonic-honeycomb iridates - and -LiIrO
A. Glamazda, P. Lemmens, S. -H. Do +2
The fractionalization of elementary excitations in quantum spin systems is a central theme in current condensed matter physics. The Kitaev honeycomb spin model provides a prominent…
Doping effects on charge density instability in non-centrosymmetric PbxTaSe2
Azat Sharafeev, Raman Sankar, Alexander Glamazda +4
We report on the investigation of vibrational and electronic properties of the Pb doped dichalcogenide PbxTaSe2 using Raman scattering experiments. We observe a marked variation of…
Lattice and orbital fluctuations in TiPO4
Dirk Wulferding, Angela Möller, Kwang-Yong Choi +7
In the s = 1/2 antiferromagnetic spin chain material TiPO4 the formation of a spin gap takes place in a two step process with two characteristic temperatures, T*=111 K and TSP=74 K…
Specific features of electron spin resonance in quasi-1D magnet β-TeVO4
Yu. Savina, A. Bludov, V. Pashchenko +3
The angular and temperature dependences of single crystal ESR spectra at X-band frequency of quasi 1D spin 1/2 antiferromagnetic zigzag chain system β-TeVO4 are reported. Two reson…
Enhanced quasiparticle dynamics of quantum well states: the giant Rashba system BiTeI and topological insulators
V. Gnezdilov, P. Lemmens, D. Wulferding +5
In the giant Rashba semiconductor BiTeI electronic surface scattering with Lorentzian linewidth is observed that shows a strong dependence on surface termination and surface potent…
Evidence for Dimer Crystal Melting in the Frustrated Spin-Ladder BiCu2PO6
K. -Y. Choi, J. W. Hwang, P. Lemmens +3
In the spin ladder compound BiCuPO there exists a decisive dynamics of spin excitations that we classify and characterize using inelastic light scattering. We observe low-e…
Softened magnetic excitations in the s = 3/2 distorted triangular antiferromagnet alpha-CaCr2O4
Dirk Wulferding, Kwang-Yong Choi, Peter Lemmens +5
The spin dynamics and magnetic excitations of the slightly distorted triangular s = 3/2 system alpha-CaCr2O4 are investigated by means of Raman spectroscopy and electron spin reson…
Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
T. Adams, A. Chacon, M. Wagner +6
We report a long-wavelength helimagnetic superstructure in bulk samples of the ferrimagnetic insulator Cu2OSeO3. The magnetic phase diagram associated with the helimagnetic modulat…
Crossover from coherent to incoherent scattering in spin-orbit dominated Sr2IrO4
Mehmet Fatih Cetin, Peter Lemmens, Vladimir Gnezdilov +5
Strong spin-orbit interaction in the two dimensional compound Sr2IrO4 leads to the formation of Jeff=1/2 isospins with unprecedented dynamics. In Raman scattering a continuum attri…
Tuning the spin dynamics of kagome systems
D. Wulferding, P. Lemmens, H. Yoshida +2
Despite the conceptional importance of realizing spin liquids in solid states only few compounds are known. On the other side the effect of lattice distortions and anisotropies on…
Magnetic properties of the antiferromagnetic spin-1/2 chain system -TeVO
Yu. Savina, O. Bludov, V. Pashchenko +3
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 pyra…
Anomalous low-energy phonons in nearly tetragonal BiFeO3 thin films
K. -Y. Choi, S. H. Do, P. Lemmens +5
We present evidence for a concomitant structural and ferroelectric transformation around K in multiferroic BiFeO/LaAlO thin films close to the tetragonal phas…
Helical fluctuations in the Raman response of the topological insulator Bi2Se3
V. Gnezdilov, Yu. G. Pashkevich, H. Berger +3
The topological insulator Bi2Se3 shows a Raman scattering response related to topologically protected surface states amplified by a resonant interband transition. Most significantl…
Magneto-structural transitions in a frustrated magnet at high fields
V. Tsurkan, S. Zherlitsyn, V. Felea +7
Ultrasound and magnetization studies of bond-frustrated ZnCr2S4 spinel are performed in static magnetic fields up to 18 T and in pulsed fields up to 62 T. At temperatures below the…
Coupled spin-lattice fluctuations in a compound with orbital degrees of freedom: the Cr based dimer system Sr3Cr2O8
Dirk Wulferding, Peter Lemmens, Kwang-Yong Choi +5
We report on an extended fluctuation regime in the spin dimer system Sr3Cr2O8 based on anomalies in Raman active phonons and magnetic scattering. The compound has two characteristi…
Anomalous optical phonons in FeTe pnictides: spin state, magnetic order, and lattice anharmonicity
V. Gnezdilov, Yu. Pashkevich, P. Lemmens +8
Polarized Raman-scattering spectra of non-superconducting, single-crystalline FeTe are investigated as function of temperature. We have found a relation between the magnitude of or…