Article
Materials Science, Multidisciplinary
Eli Zoghlin, Matthew B. Stone, Stephen D. Wilson
Summary: We report a study on the spin dynamics in the ferromagnetic chain compound Li2CuO2. Inelastic neutron scattering measurements allowed us to determine the spin Hamiltonian and resolve additional interchain exchange interactions. Our results establish Li2CuO2 as an experimental platform for studying exchange anisotropy-stabilized bound states in a ferromagnetic chain.
Article
Physics, Multidisciplinary
Wenjing Liu, Heming Zha, Gen-Da Gu, Xiaoping Shen, Mao Ye, Shan Qiao
Summary: By using spin- and angle-resolved photoemission spectroscopy, we confirmed the helical spin texture and anisotropy of spin polarizations in the nodal region of the cuprate superconductor Bi2Sr2CaCu2O8+delta. The breaking of rotational symmetry in electronic spin texture provides insights into understanding the ground state of cuprate superconductors.
CHINESE PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
M. Zhu, D. J. Voneshen, S. Raymond, O. J. Lipscombe, C. C. Tam, S. M. Hayden
Summary: In this study, we demonstrate through inelastic neutron scattering that there are low-energy collective spin fluctuations near the superconducting critical temperature and near the doping p* in cuprate superconductors. These spin fluctuations are attributed to the collapse of the pseudogap combined with an underlying tendency to magnetic order. They exist across the superconducting phase diagram and may be related to the strange metal behavior observed in overdoped cuprates.
Article
Physics, Multidisciplinary
Yi Tseng, Eugenio Paris, Kai P. Schmidt, Wenliang Zhang, Teguh Citra Asmara, Rabindranath Bag, Vladimir N. Strocov, Surjeet Singh, Justine Schlappa, Henrik M. Ronnow, Thorsten Schmitt
Summary: Studying multi-particle elementary excitations in correlated electronic materials can help us understand collective many-body phenomena and construct microscopic models. In this work, we used O K-edge resonant inelastic X-ray scattering (RIXS) to study the cuprate Sr14Cu24O41 with weakly-doped spin ladders. We found that the RIXS signal consisted of a dispersing sharp mode and a damped incoherent component, which resemble the spin-conserving ΔS = 0 two-triplon bound state and continuum excitations in the spin ladders.
COMMUNICATIONS PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
K. Matan, T. Ono, S. Ohira-Kawamura, K. Nakajima, Y. Nambu, T. J. Sato
Summary: The spin dynamics of the spin-1/2 kagome-lattice antiferromagnet Cs2Cu3SnF12 were investigated using high-resolution, time-of-flight inelastic neutron scattering. The results showed the presence of a flat mode and a low-energy dispersive mode, which can be described by the linear spin-wave theory. However, three weakly dispersive modes between 9 and 14 meV could not be explained by the theory and were suggested to be attributed to two-spinon bound states.
Article
Multidisciplinary Sciences
A. Nag, A. Nocera, S. Agrestini, M. Garcia-Fernandez, A. C. Walters, Sang-Wook Cheong, S. Johnston, Ke-Jin Zhou
Summary: This study unveils the hidden quadrupolar constituent in Y2BaNiO5 and demonstrates its unique collective dispersion using Ni L-3-edge resonant inelastic x-ray scattering.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Alexander Mitrofanov, Sergei Urazhdin
Summary: Researchers have simulated scattering of electrons on a chain of antiferromagnetically coupled quantum Heisenberg spins to analyze spin-transfer effects that classical models of magnetism cannot describe. The simulations show efficient excitation of dynamical states that are prohibited by semiclassical symmetries, such as the generation of multiple magnetic excitation quanta by a single electron. Quantum interference of spin wave functions allows for the generation of magnetization dynamics with amplitudes exceeding the transferred magnetic moment, with the excitation efficiency mainly governed by energy transfer rather than electron spin polarization. Nonclassical spin transfer may enable effective electronic control of antiferromagnets without the limitations of classical constraints.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
A. A. Zvyagin
Summary: We present an exact solution for a two-chain quantum spin model with zigzag interactions and a single chain with nearest-neighbor and next-nearest-neighbor couplings. The integrability of the model allows us to find an infinite number of integrals of motion using the algebraic Bethe ansatz. Exact results for the ground state energy and elementary excitations are obtained.
Article
Mathematics, Interdisciplinary Applications
Min Li, Boting Wang, Tao Xu, Lei Wang
Summary: This paper analyzed the bifurcations and travelling wave solutions of a general fourth-order dispersive nonlinear Schrodinger equation in a one-dimensional Heisenberg spin chain. Six types of phase portraits were obtained, and the existence of bright solitary wave, dark solitary wave, periodic wave, etc. solutions was qualitatively revealed. A quantitative correspondence between phase orbits and energy levels was established, and travelling wave solutions consistent with qualitative analysis were derived. These results can be easily applied to model nonlinear wave excitations in Heisenberg ferromagnetic spin chains.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Physics, Multidisciplinary
Sizhuo Yu, Yuan Gao, Bin-Bin Chen, Wei Li
Summary: The study introduces an unbiased and efficient approach for learning the effective Hamiltonian in correlated quantum materials through many-body analysis of thermal data. By combining strategies such as automatic gradient and Bayesian optimization with thermodynamics many-body solvers like exact diagonalization and tensor renormalization group methods, the accuracy and power of Hamiltonian learning are demonstrated. The proposed automatic approach presents a unified framework for many-body thermal data analysis in the investigations of quantum magnets and strongly correlated materials.
CHINESE PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
A. E. Feiguin, Christian Helman, A. A. Aligia
Summary: In this article, we studied a multiband Hubbard model for Cu and O orbitals in Ba2-xSrxCuO3+s, and obtained the hopping parameters from maximally localized Wannier functions derived from ab initio calculations. We derived a generalized t-J model and a one-band Hubbard model using the cell perturbation method to describe the low-energy physics of the system. We used the density matrix renormalization group method to calculate wave-vector-resolved photoemission and compared the results with recent experiments.
Article
Materials Science, Multidisciplinary
I. Panneer Muthuselvam, K. Saranya, Florian Buescher, Dirk Wulferding, Peter Lemmens, Wei-tin Chen, R. Sankar
Summary: We have successfully grown single crystals of PbMn2Ni6Te3O18 and conducted a comprehensive study of their magnetic, thermodynamic, and Raman spectroscopic properties. The magnetic susceptibility and heat capacity data reveal an antiferromagnetic phase transition around 84 K, showing hysteretic behavior, and anisotropic magnetic susceptibility with larger values for inplane fields. Raman spectroscopy has been employed to investigate lattice and magnetic excitations, revealing anomalies at characteristic temperatures around 84 K and ~200 K.
Article
Physics, Multidisciplinary
Hiroyuki Yamase, Matias Bejas, Andres Greco
Summary: Recent research shows that high-T-c cuprates can exhibit plasmon excitations, which are driven by strong correlation effects and give rise to a new quasiparticle called plasmarons. Unlike phonons and magnetic fluctuations, plasmons do not cause a kink in the electron dispersion but rather result in the emergence of a band-plasmaron in the one-particle excitation spectrum. The plasmarons are generated by bosonic fluctuations associated with local constraints and have similarities to plasmarons observed in other metallic systems.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Multidisciplinary
Leonardo Martinelli, Davide Betto, Kurt Kummer, Riccardo Arpaia, Lucio Braicovich, Daniele Di Castro, Nicholas B. Brookes, Marco Moretti Sala, Giacomo Ghiringhelli
Summary: Resonant inelastic x-ray scattering (RIXS) was used to investigate the magnetic dynamics of infinite-layer cuprate CaCuO2. It was found that the single magnon decays into a broad continuum of excitations, with the spin-flip character dominating. This continuum is proposed to originate from the decay of the magnon into spinon pairs, related to the high ring exchange J(c) of CaCuO2.
Article
Materials Science, Multidisciplinary
Zhen Ma, Zhao-Yang Dong, Jinghui Wang, Shuhan Zheng, Kejing Ran, Song Bao, Zhengwei Cai, Yanyan Shangguan, Wei Wang, M. Boehm, P. Steffens, L. -P. Regnault, Xiao Wang, Yixi Su, Shun-Li Yu, Jun-Ming Liu, Jian-Xin Li, Jinsheng Wen
Summary: The study explores the disorder effect in quantum spin liquids by investigating the magnetic-field dependence of low-energy magnetic excitations in a triangular-lattice frustrated magnet. The results demonstrate the critical role of disorder in broadening the magnetic excitation spectra and mimicking the spin-liquid features in frustrated quantum magnets.
Article
Physics, Atomic, Molecular & Chemical
A. Alfonsov, B. Buechner, V. Kataev
Summary: The study proposes the use of a cantilever-based setup to overcome challenges posed by small sample sizes, enabling detection of static magnetic response and ESR signal in novel magnetic materials samples.
APPLIED MAGNETIC RESONANCE
(2022)
Article
Chemistry, Physical
Morgan C. Allison, Sabine Wurmehl, Bernd Buechner, Joseph L. Vella, Tilo Soehnel, Sascha A. Braeuninger, Hans-Henning Klauss, Maxim Avdeev, Frederick P. Marlton, Siegbert Schmid, Chris D. Ling
Summary: FeMn3Ge2Sn7O16 is a fully ordered stoichiometric phase with an undistorted hexagonal kagome' lattice of Mn2+ cations. By replacing silicon with germanium and anisotropic high-spin Fe2+ with isotropic high-spin Mn2+, the perfection of the kagome lattice is improved, ruling out single-ion anisotropy as the driving force for the unique properties of the compounds.
CHEMISTRY OF MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Vitaliy Romaka, Ahmad Omar, Wolfgang Loeser, Bernd Buechner, Sabine Wurmehl
Summary: Investigations into the thermodynamic phase diagram of Co-based Heusler phases, focusing on the quaternary region of CoCrCoAl-CoFe, revealed critical points and immiscibility regions through DFT and thermodynamic calculations, offering valuable insights for materials design.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Olga Kataeva, Kamil Ivshin, Kirill Metlushka, Kristina Nikitina, Vera Khrizanforova, Yulia Budnikova, Robert R. Fayzullin, Shamil Latypov, Sandra Schiemenz, Michael Bretschneider, Alexey Popov, Stanislav Avdoshenko, Yulia Krupskaya, Bernd Buchner, Martin Knupfer
Summary: A series of new charge-transfer cocrystals of F(2)TCNQ with anthracene, tetracene, and chrysene were prepared and characterized. The study revealed that face-to-face pi-pi interactions are crucial for the formation of cocrystals, but lateral noncovalent interactions also play a significant role in the supramolecular arrangement and charge transfer. UV/vis spectroscopy and electronic structure quantum chemical calculations classified these cocrystals as small-gap semiconductors with energy gaps of 0.7-1.3 eV.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Nanoscience & Nanotechnology
Daniel Wolf, Sebastian Schneider, Ulrich K. Rossler, Andras Kovacs, Marcus Schmidt, Rafal E. Dunin-Borkowski, Bernd Buechner, Bernd Rellinghaus, Axel Lubk
Summary: Holographic vector-field electron tomography quantitatively reconstructed the three-dimensional magnetic texture of Bloch skyrmion tubes in FeGe with sub-10-nanometre resolution, revealing complex three-dimensional modulations and fundamental principles of skyrmion formation.
NATURE NANOTECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Rui Lou, Alexander Fedorov, Qiangwei Yin, Andrii Kuibarov, Zhijun Tu, Chunsheng Gong, Eike F. Schwier, Bernd Buechner, Hechang Lei, Sergey Borisenko
Summary: The entanglement of charge density wave (CDW), superconductivity, and topologically nontrivial electronic structure has been discovered in the kagome metal AV3Sb5 (A = K, Rb, Cs) family recently. Using high-resolution angle-resolved photoemission spectroscopy, the electronic properties of CDW and superconductivity in CsV3Sb5 are studied. The spectra around K over line exhibit a peak-dip-hump structure associated with two separate branches of dispersion, indicating the isotropic CDW gap opening below EF. The presence of a superconducting gap on both the electron band around Gamma over line and the flat band around K suggests multiband superconductivity. Our results shed light on the controversial origin of the CDW and provide insights into the relationship between CDW and superconductivity.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Lorenzo Francesco Madeo, Patrizia Sarogni, Giuseppe Cirillo, Orazio Vittorio, Valerio Voliani, Manuela Curcio, Tyler Shai-Hee, Bernd Buechner, Michael Mertig, Silke Hampel
Summary: A hybrid hydrogel was developed by loading curcumin onto graphene oxide nanosheets and blending them into an alginate hydrogel. The resulting system showed improved stability and exhibited strong anticancer effects.
Article
Materials Science, Multidisciplinary
T. Klaproth, E. Mueller, C. Habenicht, B. Buechner, M. Knupfer, M. Roslova, A. Isaeva, T. Doert, A. Koitzsch
Summary: Transition metal trichlorides exhibit peculiar and versatile magnetic properties. This study reveals that transition metal substitution can modify the optical properties of the host without compromising its electronic structure. The findings highlight the potential of material engineering in trichlorides.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Physical
Felix Talnack, Sebastian Hutsch, Michael Bretschneider, Yulia Krupskaya, Bernd Buechner, Marc Malfois, Mike Hambsch, Frank Ortmann, Stefan C. B. Mannsfeld
Summary: Polymorphism refers to the ability of many organic molecules to adopt different crystal structures without changing their chemical structure. It has been found to have an impact on the solid-state properties of organic materials, such as charge transport in organic semiconductors. In this study, a new polymorphic crystal structure of the p-type small molecule semiconductor C10-DNTT is presented. The transition between different crystal structures was observed during heating, and the thin-film crystal structure of both polymorphs was refined using optical microscopy and X-ray scattering measurements. The thermal expansion and anisotropic molecular interactions were further analyzed using density-functional theory calculations.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Felix Hansen, Rico Fucke, Titouan Charvin, Samuel Froeschke, Daniel Wolf, Romain Giraud, Joseph Dufouleur, Nico Graessler, Bernd Buechner, Peer Schmidt, Silke Hampel
Summary: This study proposes a method for the synthesis of mixed crystals of bismuth and antimony tellurides, which belong to the V2VI3 material family. The ideal synthesis conditions were determined through thermodynamic calculations and optimization experiments. The synthesized nanosheets exhibit high crystallinity and quality, with a significantly reduced carrier density compared to the binary compounds.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Chemistry, Multidisciplinary
Bertold Rasche, Julius Brunner, Tim Schramm, Madhav Prasad Ghimire, Ulrike Nitzsche, Bernd Buchner, Romain Giraud, Manuel Richter, Joseph Dufouleur
Summary: This paper presents a method using atomic force microscopy to measure the cleavage energy of van der Waals materials and quasi-two-dimensional materials. The method is validated through experiments and can be used as a tool for manipulating exfoliated flakes, offering a new route for the fabrication of nanostructures.
Article
Physics, Multidisciplinary
Seung-Ho Baek, Yeahan Sur, Kee Hoon Kim, Matthias Vojta, Bernd Buechner
Summary: Single crystals of pristine and 6% Pd-intercalated 2H-TaSe2 were studied using Se-77 nuclear magnetic resonance. The Se-77 spectrum showed line narrowing upon Pd intercalation, indicating the presence of correlated local lattice distortions above the charge density wave (CDW) transition temperature. The Knight shift data suggested a partial Fermi surface gap opening in the incommensurate CDW transition. The spin dynamics study revealed a pseudogap behavior dominating the low-energy spin excitations, which gets stronger along with superconductivity in the Pd-6% sample.
NEW JOURNAL OF PHYSICS
(2022)
Article
Multidisciplinary Sciences
S. Spachmann, P. Berdonosov, M. Markina, A. Vasiliev, R. Klingeler
Summary: High-resolution capacitance dilatometry was conducted on single crystals of Cu3Bi(SeO3)(2)O2Cl, revealing pronounced magnetoelastic coupling at 26.4(3) K and moderate effects of uniaxial pressure on T-N along the a, b, and c axes. Competing interactions were observed below 22 K. The structural phase transition at Ts showed higher sensitivity to uniaxial pressure than T-N, and magnetostriction and magnetization measurements indicated a linear magnetoelastic coupling and mixed phase behavior.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Shu-Jen Wang, Michel Panhans, Ilia Lashkov, Hans Kleemann, Federico Caglieris, David Becker-Koch, Joern Vahland, Erjuan Guo, Shiyu Huang, Yulia Krupskaya, Yana Vaynzof, Bernd Buechner, Frank Ortmann, Karl Leo
Summary: The charge and thermoelectric transport in modulation-doped large-area rubrene thin-film crystals with different crystal phases were investigated. The results showed that modulation doping, together with high-mobility crystalline organic semiconductor films, is a previously unexplored strategy for achieving high-performance organic thermoelectrics. Theoretical studies provided insight into the energy landscape of the heterostructures and its influence on qualitative trends of the Seebeck coefficient.
Article
Materials Science, Multidisciplinary
J. Arneth, M. Jonak, S. Spachmann, M. Abdel-Hafiez, Y. O. Kvashnin, R. Klingeler
Summary: In quasi-two-dimensional layered van der Waals material CrI3, the ferromagnetic ordering temperature is studied experimentally to show that compression along the c axis increases intralayer magnetic coupling, while negative in-plane strain decreases it. Interlayer exchange initially increases and subsequently decreases upon the application of both out-of-plane and in-plane compression.
