Publications (50)
Coexistence of ferromagnetic and stripe-type antiferromagnetic spin fluctuations in YFeGe
Hongliang Wo, Qisi Wang, Yao Shen +18
We report neutron scattering measurements of single-crystalline YFeGe in the normal state, which has the same crystal structure to the 122 family of iron pnictide supercond…
Strongly Enhanced Magnetic Fluctuations in a Heavy-mass Layered Ruthenate
O. Friedt, P. Steffens, M. Braden +3
We have studied the magnetic excitations in CaSrRuO, x=0.52 and 0.62, which exhibit an anomalous high susceptibility and heavy mass Fermi liquid behavior. Our inela…
Field-induced paramagnons at the metamagnetic transition in Ca1.8Sr0.2RuO4
P. Steffens, Y. Sidis, P. Link +4
The magnetic excitations in Ca1.8Sr0.2RuO4 were studied across the metamagnetic transition and as a function of temperature using inelastic neutron scattering. At low temperature a…
Strong magnetoelastic coupling at the transition from harmonic to anharmonic order in NaFe(WO) with 3d configuration
S. Holbein, M. Ackermann, L. Chapon +9
The crystal structure of the double tungstate NaFe(WO) arises from that of the spin-driven multiferroic MnWO by inserting non-magnetic Na layers. NaFe(WO) exhib…
Disorder-induced broadening of the spin waves in a triangular-lattice quantum-spin-liquid candidate YbZnGaO
Zhen Ma, Zhao-Yang Dong, Jinghui Wang +15
Disorder is important in the study of quantum spin liquids, but its role on the spin dynamics remains elusive. Here, we explore the disorder effect by investigating the magnetic-fi…
Evidence for a three-dimensional quantum spin liquid in PbCuTeO
S. Chillal, Y. Iqbal, H. O. Jeschke +9
The quantum spin liquid (QSL) is a highly entangled magnetic state characterized by the absence of static magnetism in its ground state. Instead, the spins fluctuate in a highly co…
Incommensurate antiferromagnetic fluctuations in single-crystalline LiFeAs studied by inelastic neutron scattering
N. Qureshi, P. Steffens, D. Lamago +7
We present an inelastic neutron scattering study on single-crystalline LiFeAs devoted to the characterization of the incommensurate antiferromagnetic fluctuations at $\mathbf{Q}=(0…
Spin-waves in the collinear antiferromagnetic phase of Mn$_\bf{5}$Si$_\bf{3}$
F. J. dos Santos, N. Biniskos, S. Raymond +7
By combining two independent approaches, inelastic neutron scattering measurements and density functional theory calculations, we study the spin-waves in the high-temperature colli…
Magnetic excitations in the metallic single-layer Ruthenates Ca(2-x)Sr(x)RuO(4) studied by inelastic neutron scattering
P. Steffens, O. Friedt, Y. Sidis +5
By inelastic neutron scattering, we have analyzed the magnetic correlations in the paramagnetic metallic region of the series Ca(2-x)Sr(x)RuO(4), 0.2<=x<=0.62. We find different co…
Spin fluctuations in Sr2RuO4 from polarized neutron scattering: implications for superconductivity
P. Steffens, Y. Sidis, J. Kulda +4
Triplet pairing in Sr2RuO4 was initially suggested based on the hypothesis of strong ferromagnetic spin fluctuations. Using polarized inelastic neutron scattering, we accurately de…
Magnon dispersion in Ca2RuO4: impact of spin-orbit coupling and oxygen moments
S. Kunkemöller, E. Komleva, S. V. Streltsov +6
The magnon dispersion of CaRuO has been studied by polarized and unpolarized neutron scattering experiments on crystals containing 0, 1 and 10 % of Ti. The entire dispersio…
Hourglass dispersion in overdoped single-layered manganites
H. Ulbrich, P. Steffens, D. Lamago +2
The excitation spectrum in single-layered Nd(0.33)Sr(1.67)MnO4 and Pr(0.33)Ca(1.67)MnO4 resembles the hourglass-like excitation dispersion seen in various cuprates superconductors.…
An overview of the spin dynamics of antiferromagnetic MnSi
N. Biniskos, F. J. dos Santos, M. dos Santos Dias +8
The metallic compound MnSi hosts a series of antiferromagnetic phases which can be controlled by external stimuli such as temperature and magnetic field. In this work, we i…
Anisotropy of incommensurate magnetic excitations in slightly overdoped BaKFeAs probed by polarized inelastic neutron scattering experiments
N. Qureshi, C. H. Lee, K. Kihou +3
Polarized neutron scattering experiments on the slightly overdoped superconductor BaKFeAs reveal broad magnetic resonance scattering peaking at approximatel…
Suppression of low-energy longitudinal spin-excitations in Co-underdoped BaFe2As2
F. WaÃer, C. H. Lee, K. Kihou +4
Polarized inelastic neutron scattering experiments were performed to study magnetic excitations in the normal and superconducting phases of Co-underdoped BaFeAs, which exhi…
Magnon dispersion in ferromagnetic SrRuO
K. Jenni, S. Kunkemöller, A. Tewari +6
The magnetic excitations in ferromagnetic SrRuO were studied by inelastic neutron scattering combining experiments on triple-axis and time-of-flight spectrometers with and with…
Magnetoelastic coupling across the metamagnetic transition in CaSrRuO (0.2 < x < 0.5)
J. Baier, P. Steffens, O. Schumann +11
The magnetoelastic coupling in CaSrRuO and in CaSrRuO has been studied combining high-resolution dilatometer and diffraction techniques. Bot…
Multiple scattering camouflaged as magnetic stripes in single crystals of superconducting (La,Sr)CuO
A. -E. Å¢uÅ£ueanu, T. B. Tejsner, M. E. LÇcÇtuÅu +6
Neutron diffraction has been a very prominent tool to investigate high-temperature superconductors, in particular through the discovery of an incommensurate magnetic signal known a…
Low-dimensional antiferromagnetic fluctuations in the heavy-fermion paramagnetic ladder UTe
W. Knafo, G. Knebel, P. Steffens +7
Inelastic-neutron-scattering measurements were performed on a single crystal of the heavy-fermion paramagnet UTe above its superconducting temperature. We confirm the presence…
Spin-fluctuations drive the inverse magnetocaloric effect in Mn5Si3
N. Biniskos, K. Schmalzl, S. Raymond +4
Inelastic neutron scattering measurements were performed on single crystals of the antiferromagnetic compound Mn5Si3 in order to investigate the relation between the spin dynamics…
Universality of dispersive spin-resonance mode in superconducting BaFe2As2
C. H. Lee, P. Steffens, N. Qureshi +5
Spin fluctuations in superconducting BaFe2(As1-xPx)2 (x=0.34, Tc = 29.5 K) are studied using inelastic neutron scattering. Well-defined commensurate magnetic signals are observed a…
Thermodynamic Properties of (Ca,Sr)RuO in Magnetic Fields
J. Baier, T. Zabel, M. Kriener +9
We have studied the influence of a magnetic field on the thermodynamic properties of CaSrRuO in the intermediate metallic region with tilt and rotational distorti…
Inhomogeneous spin excitations in weakly coupled spin-1/2 chains
L. Shen, E. Campillo, O. Zaharko +8
We present a systematic inelastic neutron scattering and neutron diffraction study of the magnetic structure of the quasi-1D spin-1/2 magnet SrCo2V2O8, where the interchain couplin…
Electron-Spin Excitation Coupling in an Electron Doped Copper Oxide Superconductor
Jun Zhao, F. C. Niestemski, Shankar Kunwar +8
High-temperature (high-Tc) superconductivity in the copper oxides arises from electron or hole doping of their antiferromagnetic (AF) insulating parent compounds. The evolution of…
Highly anisotropic magnon dispersion in Ca2RuO4: evidence for strong spin orbit coupling
S. Kunkemöller, D. Khomskii, P. Steffens +3
The magnon disp ersion in Ca2RuO4 has been determined by inelastic neutron scattering on single crytals containing 1% of Ti. The dispersion is well described by a conventional Heis…
Incommensurate magnetic excitations in superconducting LiFeAs
N. Qureshi, P. Steffens, Y. Drees +8
Magnetic correlations in superconducting LiFeAs were studied by elastic and by inelastic neutron scattering experiments. There is no indication for static magnetic ordering but ine…
Local magnetic anisotropy in BaFeAs: a polarized inelastic neutron scattering study
N. Qureshi, P. Steffens, S. Wurmehl +3
The anisotropy of the magnetic excitations in BaFeAs was studied by polarized inelastic neutron scattering which allows one to separate the components of the magnetic respo…
Strong Interplay between Stripe Spin Fluctuations, Nematicity and Superconductivity in FeSe
Qisi Wang, Yao Shen, Bingying Pan +13
Elucidating the microscopic origin of nematic order in iron-based superconducting materials is important because the interactions that drive nematic order may also mediate the Coop…
High pressure diffraction studies on Ca2RuO4
P. Steffens, O. Friedt, P. Alireza +8
We studied the crystal and magnetic structure of Ca2RuO4 by different diffraction techniques under high pressure. The observed first order phase transition at moderate pressure (0.…
Vortex Crystal Candidate in the Triangular Quantum Antiferromagnet
J. Nagl, K. Yu. Povarov, B. Duncan +16
The prospect of merging the paradigms of geometric frustration on a triangular lattice and bond anisotropies in the strong spin-orbit coupling limit holds tremendous promise in the…
Strong Spin Resonance Mode associated with suppression of soft magnetic ordering in Hole-doped Ba1-xNaxFe2As2
F. Wasser, J. -T. Park, S. Aswartham +6
Spin-resonance modes (SRM) are taken as evidence for magnetically driven pairing in Fe-based superconductors, but their character remains poorly understood. The broadness, the spli…
Pseudospin-lattice coupling in the spin-orbit Mott insulator Sr2IrO4
J. Porras, J. Bertinshaw, H. Liu +15
Spin-orbit entangled magnetic dipoles, often referred to as pseudospins, provide a new avenue to explore novel magnetism inconceivable in the weak spin-orbit coupling limit, but th…
Spin waves and three-dimensionality in the high-pressure antiferromagnetic phase of SrCu(BO)
E. Fogh, G. Giriat, M. E. Zayed +11
Quantum magnetic materials can provide explicit realizations of paradigm models in quantum many-body physics. In this context, SrCu(BO) is a faithful realization of the…
Field-induced electronic phase separation in the high-temperature superconductor LaSrCuO
S. Holm-Dahlin, J. Larsen, H. Jacobsen +14
We present a combined neutron diffraction and high field muon spin rotation (SR) study of the magnetically ordered and superconducting phases of the high-temperature supercondu…
Absence of a large superconductivity-induced gap in magnetic fluctuations of Sr2RuO4
S. Kunkemöller, P. Steffens, P. Link +3
Inelastic neutron scattering experiments on Sr2RuO4 determine the spectral weight of the nesting induced magnetic fluctuations across the superconducting transition. There is no ob…
Cascade of magnetic-field-driven quantum phase transitions in Ce3Pd20Si6
F. Mazza, P. Y. Portnichenko, S. Avdoshenko +8
Magnetically hidden order is a hypernym for electronic ordering phenomena that are visible to macroscopic thermodynamic probes but whose microscopic symmetry cannot be revealed wit…
Neutron scattering studies on spin fluctuations in SrRuO
K. Jenni, S. Kunkemöller, P. Steffens +5
The magnetic excitations in SrRuO are studied by polarized and unpolarized neutron scattering experiments as a function of temperature. At the scattering vector of the Ferm…
Effect of Nd and Rh substitution on the spin dynamics of Kondo insulator CeFe2Al10
P. A. Alekseev, J. -M. Mignot, D. T. Adroja +7
The dynamic magnetic properties of the Kondo-insulator state in CeFe2Al10 (spin gap, resonance mode) have been investigated using polarized neutrons on a single crystal of pure CeF…
Anisotropy of the incommensurate fluctuations in Sr2RuO4: a study with polarized neutrons
M. Braden, P. Steffens, Y. Sidis +4
The anisotropy of the magnetic incommensurate fluctuations in Sr2RuO4 has been studied by inelastic neutron scattering with polarized neutrons. We find a sizeable enhancement of th…
Spin Resonance and Magnetic Order in an Unconventional Superconductor
D. G. Mazzone, S. Raymond, J. L. Gavilano +4
Unconventional superconductivity in many materials is believed to be mediated by magnetic fluctuations. It is an open question how magnetic order can emerge from a superconducting…
Topological magnon band structure of emergent Landau levels in a skyrmion lattice
T. Weber, D. M. Fobes, J. Waizner +16
The motion of a spin excitation across topologically non-trivial magnetic order exhibits a deflection that is analogous to the effect of the Lorentz force on an electrically charge…
Weak three-dimensional coupling of Heisenberg quantum spin chains in SrCuTeO
S. Chillal, A. T. M. N. Islam, P. Steffens +2
The magnetic Hamiltonian of the Heisenberg quantum antiferromagnet SrCuTeO is studied by inelastic neutron scattering technique on powder and single crystalline samples…
Structural aspects of metamagnetism in Ca_{2-x}Sr_{x}RuO_4 (0.2 < x < 0.5): field tuning of orbital occupation
M. Kriener, P. Steffens, J. Baier +12
The crystal structure of Ca_{2-x}Sr_xRuO_4 with 0.2 < x < 1.0 has been studied by diffraction techniques and by high resolution capacitance dilatometry as a function of temperature…
Commensurate antiferromagnetic excitations as a signature of the pseudogap in the tetragonal high-Tc cuprate HgBaCuO
M. K. Chan, C. J. Dorow, L. Mangin-Thro +12
Antiferromagnetic correlations have been argued to be the cause of the d-wave superconductivity and the pseudogap phenomena exhibited by the cuprates. Although the antiferromagneti…
Evidence for charge orbital and spin stripe order in an overdoped manganite
H. Ulbrich, D. Senff, P. Steffens +5
We present diffraction data on a single-layered manganite La(0.42)Sr(1.58)MnO4 with hole doping (x>0.5). Overdoped La(0.42)Sr(1.58)MnO4 exhibits a complex ordering of charges, orbi…
Evidence for a spinon Fermi surface in a triangular lattice quantum spin liquid candidate
Yao Shen, Yao-Dong Li, Hongliang Wo +16
A quantum spin liquid is an exotic quantum state of matter in which spins are highly entangled and remain disordered down to zero temperature. Such a state of matter is potentially…
Spin dynamics of the quantum dipolar magnet YbGaO in an external field
E. Lhotel, L. Mangin-Thro, E. Ressouche +7
We investigate ytterbium gallium garnet YbGaO in the paramagnetic phase above the supposed magnetic transition at mK. Our study combines suscep…
Spin-wave dispersion and magnon chirality in multiferroic TbMnO3
S. Holbein, P. Steffens, S. Biesenkamp +4
Inelastic neutron scattering experiments combining time-of-flight and polarized techniques yield a comprehensive picture of the magnon dispersion in multiferroic TbMnO3 including t…
Fractionalized excitations in the partially magnetized spin liquid candidate YbMgGaO4
Yao Shen, Yao-Dong Li, H. C. Walker +7
Quantum spin liquids (QSLs) are exotic states of matter characterized by emergent gauge structures and fractionalized elementary excitations. The recently discovered triangular lat…
Two Ising-like magnetic excitations in a single-layer cuprate superconductor
Yuan Li, G. Yu, M. K. Chan +10
There exists increasing evidence that the phase diagram of the high-transition temperature (Tc) cuprate superconductors is controlled by a quantum critical point. One distinct theo…