المؤلفون: Ruitang Wang, Haidan Wen, J. Sun, Junyi Yang, Anthony DiChiara, Xuerong Liu, Hong Ding, Jiaqi Lin, Mark Dean, Derek Meyers, Gang Li, Yue Cao, Jian Liu

المصدر: Physical Review X. 11

مصطلحات موضوعية: Materials science, Magnetic order, Physics::Optics, General Physics and Astronomy, equipment and supplies, Laser, Pulse (physics), law.invention, Dimension (vector space), law, Thermal limit, Atomic physics, human activities, Ultrashort pulse

الوصف: Ultrafast laser stimulation of 3D magnetic order in a layered material produces a well-ordered magnetic state in two dimensions that is fractured into thin domains in the third dimension.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::d1a203e7b8977e5d2e885e1101ac5c72Test
https://doi.org/10.1103/physrevx.11.041023Test

المؤلفون: Jiatai Feng, John F. Mitchell, Y. Shen, Ignace Jarrige, M. Garcia-Fernandez, Antia S. Botana, P. Villar Arribi, Ke-Jin Zhou, Jiaqi Lin, Mark Dean, A. C. Walters, Valentina Bisogni, G. Fabbris, Hu Miao, S. G. Chiuzbaian, Jonathan Pelliciari, Derek Meyers, Abhishek Nag, Junjie Zhang, Xiaopei Liu, M. R. Norman, John W. Freeland, D. G. Mazzone

المصدر: Physical Review Letters. 126

مصطلحات موضوعية: Physics, Superconductivity, Condensed matter physics, Magnon, General Physics and Astronomy, 01 natural sciences, Computer Science::Other, Magnetic exchange, Resonant inelastic X-ray scattering, Condensed Matter::Materials Science, Superexchange, Condensed Matter::Superconductivity, 0103 physical sciences, Condensed Matter::Strongly Correlated Electrons, Cuprate, 010306 general physics, Spectroscopy

الوصف: The discovery of superconductivity in a d(9-delta) nickelate has inspired disparate theoretical perspectives regarding the essential physics of this class of materials. A key issue is the magnitude of the magnetic superexchange, which relates to whether cuprate-like high-temperature nickelate superconductivity could be realized. We address this question using Ni L-edge and O K-edge spectroscopy of the reduced d(9-1/3) trilayer nickelates R4Ni3O8 (where R = La, Pr) and associated theoretical modeling. A magnon energy scale of similar to 80 meV resulting from a nearest-neighbor magnetic exchange of J = 69(4) meV is observed, proving that d(9-delta) nickelates can host a large superexchange. This value, along with that of the Ni-O hybridization estimated from our O K-edge data, implies that trilayer nickelates represent an intermediate case between the infinite-layer nickelates and the cuprates. Layered nickelates thus provide a route to testing the relevance of superexchange to nickelate superconductivity.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::8d8360e060fdfb9ea6cf4bf26037de21Test
https://doi.org/10.1103/physrevlett.126.087001Test

المؤلفون: D. G. Mazzone, Naoki Momono, A. C. Walters, Migaku Oda, K. Kurosawa, M. Garcia-Fernandez, Ignace Jarrige, Abhishek Nag, Xiaopei Liu, Andi Barbour, Jonathan Pelliciari, Hu Miao, Ke-Jin Zhou, Jiaqi Lin, Mark Dean, Valentina Bisogni, G. D. Gu

المصدر: Physical Review Letters. 124

مصطلحات موضوعية: Physics, Condensed matter physics, Magnetism, Scattering, Phonon, Doping, General Physics and Astronomy, Fermi surface, 01 natural sciences, Spectral line, Condensed Matter::Superconductivity, 0103 physical sciences, Condensed Matter::Strongly Correlated Electrons, Cuprate, 010306 general physics, Charge density wave

الوصف: The discovery of charge-density-wave-related effects in the resonant inelastic x-ray scattering spectra of cuprates holds the tantalizing promise of clarifying the interactions that stabilize the electronic order. Here, we report a comprehensive resonant inelastic x-ray scattering study of La_{2-x}Sr_{x}CuO_{4} finding that charge-density wave effects persist up to a remarkably high doping level of x=0.21 before disappearing at x=0.25. The inelastic excitation spectra remain essentially unchanged with doping despite crossing a topological transition in the Fermi surface. This indicates that the spectra contain little or no direct coupling to electronic excitations near the Fermi surface, rather they are dominated by the resonant cross section for phonons and charge-density-wave-induced phonon softening. We interpret our results in terms of a charge-density wave that is generated by strong correlations and a phonon response that is driven by the charge-density-wave-induced modification of the lattice.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::8c3ae94034b417d279a5b770f47a7d73Test
https://doi.org/10.1103/physrevlett.124.207005Test

المؤلفون: Jenia Karapetrova, Lin Hao, Jong-Woo Kim, Qi Cui, Jinguang Cheng, Junyi Yang, Lu Zhang, Huaixin Yang, Xuerong Liu, Jian Liu, Lukáš Horák, Jiaqi Lin, Mark Dean, Philip Ryan

المصدر: Physical Review Materials. 3

مصطلحات موضوعية: Materials science, Physics and Astronomy (miscellaneous), Spintronics, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Pulsed laser deposition, Condensed Matter::Materials Science, Crystallography, Octahedron, Ferromagnetism, Lattice (order), 0103 physical sciences, Antiferromagnetism, Condensed Matter::Strongly Correlated Electrons, General Materials Science, 010306 general physics, 0210 nano-technology, Ground state, Spin canting

الوصف: $5d$ iridates have shown vast emergent phenomena due to a strong interplay among their lattice, charge, and spin degrees of freedom, because of which the potential in spintronic application of the thin-film form is highly leveraged. Here we have epitaxially stabilized perovskite $\mathrm{SrI}{\mathrm{r}}_{0.8}\mathrm{S}{\mathrm{n}}_{0.2}{\mathrm{O}}_{3}$ on [001] $\mathrm{SrTi}{\mathrm{O}}_{3}$ substrates through pulsed laser deposition and systematically characterized the structural, electronic, and magnetic properties. Physical property measurements unravel an insulating ground state with a weak ferromagnetism in the compressively strained epitaxial film. The octahedral rotation pattern is identified by synchrotron x-ray diffraction, resolving a mix of ${a}^{+}{b}^{\ensuremath{-}}{c}^{\ensuremath{-}}$ and ${a}^{\ensuremath{-}}{b}^{+}{c}^{\ensuremath{-}}$ domains. X-ray magnetic resonant scattering directly demonstrates a G-type antiferromagnetic structure of the magnetic order and the spin canting nature of the weak ferromagnetism.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::b5fab547fa868013f613ad35fa43a94bTest
https://doi.org/10.1103/physrevmaterials.3.124411Test

المؤلفون: Hechang Lei, Zhong Fang, Qi Wang, Jiaqi Lin, Mark Dean, Hongming Weng, Yue Cao, Gilberto Fabbris, Xuerong Liu, Hu Miao, Ayman Said, Tiantian Zhang

المصدر: Physical Review Letters. 123

مصطلحات موضوعية: Materials science, Phonon, Scattering, Spectrum (functional analysis), Structure (category theory), General Physics and Astronomy, Coupling (probability), 01 natural sciences, Symmetry (physics), Quantum mechanics, 0103 physical sciences, 010306 general physics, Degeneracy (mathematics), Realization (systems)

الوصف: While condensed matter systems host both Fermionic and Bosonic quasi-particles, reliably predicting and empirically verifying topological states is only mature for Fermionic electronic structures, leaving topological Bosonic excitations sporadically explored. This is unfortunate, as Bosonic systems such a phonons offer the opportunity to assess spinless band structures where nodal lines can be realized without invoking special additional symetries to protect against spin-orbit coupling. Here we combine first-principles calculations and meV-resolution inelastic x-ray scattering to demonstrate the first realization of parity-time reversal ($\mathcal{PT}$) symmetry protected helical nodal lines in the phonon spectrum of MoB$_{2}$. This structure is unique to phononic systems as the spin-orbit coupling present in electronic systems tends to lift the degeneracy away from high-symmetry locations. Our study establishes a protocol to accurately identify topological Bosonic excitations, opening a new route to explore exotic topological states in crystalline materials.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::b9dfba780cadd3abe84dc73a73bd9695Test
https://doi.org/10.1103/physrevlett.123.245302Test