Article
Physics, Multidisciplinary
Ling-Fang Lin, Yang Zhang, Gonzalo Alvarez, Adriana Moreo, Elbio Dagotto
Summary: By analyzing the competition between ferromagnetic and antiferromagnetic tendencies, as well as the interplay of hoppings, Coulomb interactions, Hund's coupling, and crystal-field splittings in the iron oxychalcogenide Ce2O2FeSe2, it was found that large entanglements between doubly occupied and half filled orbitals play a key role in stabilizing the FM order. Computational techniques applied to a multiorbital Hubbard model confirmed the proposed FM mechanism.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Erin S. Grant, Liam T. Hall, Lloyd C. L. Hollenberg, Gawain McColl, David A. Simpson
Summary: In this study, the magnetic properties of ferritin, the primary storage protein in the body, were systematically studied using diamond-based quantum spin relaxometry. An anomalous magnetic behavior was observed at relatively low iron loads due to a morphological change in the iron core of ferritin. The inclusion of this morphological change in a theoretical model was supported by electron microscopy studies and provided evidence for the magnetic consequence of the morphological change.
Article
Chemistry, Multidisciplinary
Tuan Dung Nguyen, Jinbao Jiang, Bumsub Song, Minh Dao Tran, Wooseon Choi, Ji Hee Kim, Young-Min Kim, Dinh Loc Duong, Young Hee Lee
Summary: The study demonstrates gate-tunable magnetic order via resonant Se vacancies in WSe2, which is confirmed by density functional calculations. The observation of Se-vacancy states through photo-excited carrier recombination, and the splitting of energy levels with increasing laser power, presents a new approach for controlling the magnetic properties of defects in vdW-layered semiconductors.
Article
Nanoscience & Nanotechnology
Qiaolu Lin, Licheng Miao, Zhengfang Qian, Yiling Sun, Renheng Wang
Summary: In this study, the magnetism of borophene nanosheets with specific vacancy defects was investigated using first-principles calculations. The results show that the magnetism is caused by asymmetrical orbital occupied states and influenced by localized charge redistribution. The ground state is ferromagnetic with an anisotropic interaction, and the magnetic moment is affected by the concentration and distribution of vacancies, as well as carriers and pressure.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Physical
Moloud Kaviani, Ulrich Aschauer
Summary: Complex oxide functionality, such as ferroelectricity, magnetism or superconductivity, is often achieved in epitaxial thin-film geometries. However, the stability and electronic structure of oxygen vacancies, which are the dominant type of defect in these materials, have been primarily studied in bulk or strained bulk, neglecting the interfaces and surfaces present in thin-film geometries. In this study, density functional theory calculations were used to investigate oxygen vacancies in a SrMnO3 thin film grown on a SrTiO3 substrate. The results show that surface and interface effects lead to significant differences in the stability and electronic structure of oxygen vacancies in thin-film geometries compared to the (strained) bulk.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Hayato Yatsuzuka, Yuya Haraguchi, Akira Matsuo, Koichi Kindo, Hiroko Aruga Katori
Summary: New Ru4+ double perovskite oxides have been successfully synthesized, showing unexpected magnetic properties and the potential presence of isolated spins.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Environmental
Jianbo Li, Yanxia Wang, Xiong Yang, Huijun Kang, Zhiqiang Cao, Xue Jiang, Zongning Chen, Enyu Guo, Tongmin Wang
Summary: By doping La and generating stable oxygen vacancies, the study successfully transformed CaTiO3 into a material with outstanding TE properties. The La-doped samples exhibited significantly enhanced power factor over a broad temperature range and achieved a higher zT value.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Materials Science, Multidisciplinary
Grgur Palle, Owen Benton
Summary: The study explores a special limit of the XXZ model on the kagome lattice, suggesting it as a starting point for discovering quantum spin systems with mixed ordered and spin-liquid-like properties. The research shows that the ground states along a specific line in the XYZ model exhibit partial order and a coexistence of infinite-range correlations and undetermined degrees of freedom.
Article
Physics, Applied
H. Liu, R. Knut, S. Saha, R. S. Malik, K. Jatkar, R. Stefanuik, J. Soederstroem, J. E. Shoup, Durga Khadka, T. R. Thapaliya, S. X. Huang, A. Gupta, O. Karis, D. Karaiskaj, D. A. Arena
Summary: The study presents all-optical investigations of spin dynamics in two classes of ferrimagnets, revealing non-monotonic variations in spin dynamics in different ferrimagnets as well as non-trivial interactions between spin excitations on different magnetic sub-lattices.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Afifa Yousaf, S. Nazir
Summary: This study investigates the electronic, magnetic, and ferroelectric properties of Pb2CoTeO6 material under different strains using first-principles calculations. The results show significant spontaneous polarization and magnetocrystalline anisotropy constant in the material, which have potential applications in optics and solar cell industry.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Andrew C. Lang, D. Scott Katzer, Neeraj Nepal, David J. Meyer, Rhonda M. Stroud
Summary: Epitaxial transition metal nitrides (TMNs) are a new class of crystalline thin film metals that can be integrated with common group III-nitride semiconductors. This study used high-resolution transmission electron microscopy to identify different phases of tantalum nitrides with N-sublattice ordering, revealing Ta-deficient films with specific planar defects. These findings lay the foundation for the application of this epitaxial TMN material in new electronic and superconducting device structures.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Condensed Matter
Yinmei Yuan, Hu Jia, Chaoxiang Li, Liu Tang, Hong Zhang, Wei Sun
Summary: The study investigated the effects of vacancies on wurtzite AlN surfaces through CASTEP calculations, revealing that introducing vacancies led to a metallic characteristic with zero band gap. The presence of vacancies did not significantly impact the absorption and reflection of the AlN systems. The original systems were found to be ferrimagnetic, whereas the systems with vacancies exhibited non-magnetic behavior.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
Morihiko Nishida, Kota Katsumi, Dongjoon Song, Hiroshi Eisaki, Ryo Shimano
Summary: We investigated the photoexcited transient responses of the stripe-ordered phase in a cuprate superconductor, La1.6-xNd0.4SrxCuO4 (x = 0.12), using optical-pump terahertz (THz)-probe spectroscopy. Upon near-infrared photoexcitation, a plasma edge appeared in the THz reflection spectrum along the c axis, indicating the interplay between the light-induced phase and the charge-stripe order. The optical conductivity spectrum of the light-induced state was mostly reproduced by the Drude model with a small scattering rate.
Article
Materials Science, Multidisciplinary
Linjie Wu, Yongjia Zhang, Zhongquan Nie, Ensi Cao
Summary: Introducing magnetism into high Curie temperature ferroelectric Ca2Nb2O7 can make it a potential multiferroic material at room temperature. Experimentally and theoretically, it was shown that the ferromagnetic behavior in the Ca2Nb1.9O7-delta film is induced by the complex vacancy of VNb+O, providing new insights into the feasibility of introducing ferromagnetism into Ca2Nb2O7 film.
FRONTIERS IN MATERIALS
(2021)
Article
Chemistry, Physical
Sho Goto, Hiroaki Kura, Masahito Tsujikawa, Masafumi Shirai, Keita Ito, Takashi Suemasu, Koki Takanashi, Hideto Yanagihara
Summary: Tetragonally ordered Fe2Ni2N powder was synthesized successfully from L1(0)-FeNi using a nitrogen topotactic reaction. The material exhibits high magnetic anisotropy energy and has a thermal decomposition temperature of 667 K and a Curie temperature of 441 K.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Multidisciplinary
Niraj Aryal, Xilian Jin, Q. Li, A. M. Tsvelik, Weiguo Yin
Summary: The study of phonon-space topology surfaces provides important insights into the topological transition, emergence of Dirac semimetal states, and the generation of Weyl modes in ZrTe5, offering a new approach to understand and utilize the exotic physical properties of these materials.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
R. J. Koch, R. Sinclair, M. T. McDonnelle, R. Yu, M. Abeykoon, M. G. Tucker, A. M. Tsvelik, S. J. L. Billinge, H. D. Zhou, W-G Yin, E. S. Bozin
Summary: Through examining the local structure of NaTiSi2O6, it was found that there is a preexisting local symmetry breaking before the Ti-dimerization orbital-assisted Peierls transition at 210 K. The dimers evolve into a short range orbital degeneracy lifted (ODL) state with dual orbital character as the temperature increases, persisting up to at least 490 K. The ODL state is correlated over a length scale spanning about 6 sites of the Ti zigzag chains, suggesting that the ODL phenomenology extends to strongly correlated electron systems.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Junjie Li, Lijun Wu, Shan Yang, Xilian Jin, Wei Wang, Jing Tao, Lynn Boatner, Marcus Babzien, Mikhail Fedurin, Mark Palmer, Weiguo Yin, Olivier Delaire, Yimei Zhu
Summary: Photoinduced ultrafast phase transitions can generate novel emergent properties, and accurately probing transient atomic structures and dynamics is crucial for understanding and controlling the interaction between electrons and lattice. In this study, using both experimental and computational methods, we investigate the lattice distortion and phase transition process of VO2, providing important insights into the quantification of phase fraction and the role of thermal heating. These findings contribute to a better understanding of photoinduced transitions.
Article
Chemistry, Physical
Niraj Aryal, Xilian Jin, Qiang Li, Mengkun Liu, A. M. Tsvelik, Weiguo Yin
Summary: Ultrafast control of structural and electronic properties of quantum materials, such as ZrTe5, has become a topic of great interest. Researchers have discovered that lattice distortions in ZrTe5 can switch the system from a topological insulator to a Weyl semimetal, enabling the realization of robust and highly tunable Weyl phases. The induced Berry curvature dipole moment also leads to various nonlinear effects that oscillate with the amplitude of the phonon modes, providing an ultrafast switch for controlling the Weyltronics-enabled quantum system.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Physics, Multidisciplinary
Zi-Jian Lang, Fan Yang, Wei Ku
Summary: Recent observations in cuprate high-temperature superconductors show that increasing carrier density leads to a decrease in superfluid phase stiffness, contrary to the quantum density-phase conjugation theory. Analytic estimation and Monte Carlo calculations were performed to study the underlying mechanisms, revealing that the special properties of the carriers can cause enhanced phase fluctuation with increasing density. This finding suggests a new paradigm for understanding unconventional superconductivity in strongly correlated materials based on bosonic superfluidity.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Y. Shen, J. Sears, G. Fabbris, A. Weichselbaum, W. Yin, H. Zhao, D. G. Mazzone, H. Miao, M. H. Upton, D. Casa, R. Acevedo-Esteves, C. Nelson, A. M. Barbour, C. Mazzoli, G. Cao, M. P. M. Dean
Summary: In this study, we used resonant x-ray scattering to investigate Ba4Ir3O10 and found the existence of a one-dimensional spinon continuum. Magnetic order appeared when an equivalent amount of strontium was doped and exact diagonalization calculations confirmed that the frustrated intratrimer interactions effectively reduced the system into decoupled spin chains.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
D. Nevola, N. Zaki, J. M. Tranquada, W. -G. Yin, G. D. Gu, Q. Li, P. D. Johnson
Summary: An intense debate has arisen recently regarding the changes induced by light in iron-chalcogenide superconductors, specifically the enhancement of superconductivity and the emergence of a metastable state. Through high-energy resolution techniques, we directly observe the melting of superconductivity on ultrafast timescales. Our results demonstrate a non-equilibrium response on short timescales, with the gap filling in before the destruction of the superconducting peak, followed by a metastable response. We propose that pair phase decoherence and an increase in double-stripe correlations competing with superconductivity could explain these observations. These findings contribute to the exciting advancements in iron-based superconductors and suggest that the photoinduced metastable state may compete with superconductivity.
Article
Materials Science, Multidisciplinary
Jackson Lee, Matthew R. Carbone, Weiguo Yin
Summary: In this study, two machine-learning techniques, K-nearest neighbor regression (KNN) and a feed-forward neural network (FFNN), were used to investigate the spectral functions of a mobile hole in the t-t'-t''-J model. The results show that both methods accurately and efficiently predict spectral functions in the forward problem, and the FFNN is capable of accurately predicting model parameters in the inverse problem. This suggests the potential use of deep-learning methods in predicting materials parameters from experimentally measured spectral functions.
Article
Materials Science, Multidisciplinary
Niraj Aryal, Qiang Li, A. M. Tsvelik, Weiguo Yin
Summary: This paper investigates the electronic structure and magnetic properties of EuZnSb2, a layered antiferromagnetic square-net topological semimetal, using first-principles and effective Hamiltonian methods. The study reveals that small changes in the band structure caused by magnetic ordering and changes in the orientation of the Neel vector have amplified effects on transport properties like spin Hall conductivity. The research predicts that the broken symmetry introduced by the ordering of the Neel vector is more pronounced in the surface electronic dispersion rather than in the bulk, suggesting that surface probes may be better suited for measuring these effects. The coexistence of magnetism with many other competing phases makes this material interesting and potentially useful for quantum spintronics applications.
Article
Materials Science, Multidisciplinary
Robert J. Koch, Niraj Aryal, Oleh Ivashko, Yu Liu, Milinda Abeykoon, Eric D. Bauer, Martin V. Zimmermann, Weiguo Yin, Cedomir Petrovic, Emil S. Bozin
Summary: This study reports on a high-temperature local symmetry breaking phenomenon in binary ruthenium pnictides and analyzes its correlation with superconductivity. It is found that local distortions exist in the pseudogap regime, and these distortions are significantly enhanced when the nonmagnetic ground state is established. These findings may play an important role in the emergence of superconductivity.
Article
Physics, Multidisciplinary
Yuting Tan, Tianyu Zhang, Tao Zou, A. M. Dos Santos, Jin Hu, Dao-Xin Yao, Z. Q. Mao, Xianglin Ke, Wei Ku
Summary: A counterintuitive enhancement of quantum fluctuation with larger spins is discovered in studying the emergent magnetism in high-temperature superconductor FeSe under pressure. The larger spins in FeSe suffer even stronger long-range quantum fluctuations that diminish their ordering at ambient pressure, but the ordering can develop above 1 GPa due to weakened fluctuation.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Yu Liu, A. M. Milinda Abeykoon, Niraj Aryal, David Graf, Zhixiang Hu, Weiguo Yin, C. Petrovic
Summary: We conducted a thermal transport study on IrSbSe and found that it exhibits a narrow-gap semiconducting behavior and a polaronic transport mechanism. The dominant conduction mechanism changes from Mott variable-range hopping to another mechanism with decreasing temperature. In addition, IrSbSe has a low thermal conductivity and thermopower, but a high vacancy defect concentration, suggesting the potential for improving carrier density through chemical substitution or defect optimization.
Article
Materials Science, Multidisciplinary
P. M. Lozano, Gabriel Cardoso, Niraj Aryal, Genda Gu, Alexei Tsvelik, Weiguo Yin, Qiang Li
Summary: This study investigates the anomalous Hall effect in Zirconium pentatelluride ZrTe5, a topological semimetal, by combining experimental and theoretical approaches. The results show that the anomalous Hall contribution dominates the Hall response in a narrow temperature window around the Lifshitz transition, while the orbital contribution dominates away from it. The study also reveals a coexistence of a topological phase transition with the Lifshitz transition in ZrTe5.
Article
Optics
Xiang Li, Thors Hans Hansson, Wei Ku
Summary: The Aharonov-Bohm effect is a quantum effect that causes a measurable phase shift in the wave function of a charged particle encircling an inaccessible magnetic flux. While classically believed to be impossible, quantum mechanics reveals a local coupling between the particle's current and the electromagnetic vector potential A, extending beyond the region of finite magnetic field. This suggests the fundamental nature of A over B in quantum mechanics, despite A being unobservable.
Article
Materials Science, Multidisciplinary
Zi-Jian Lang, Ruoshi Jiang, Wei Ku
Summary: Researchers suggest that nickel chalcogenides may be a promising family of materials for improving superconducting properties, with low-energy physics closer to that of the cuprates and stronger magnetic interaction than the nickelates. This proposal also opens up the possibility of parameter tuning through ligand substitution among chalcogenides to further enhance superconducting properties.
