The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Silke Biermann - One of the best experts on this subject based on the ideXlab platform.
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reduced effective spin orbital degeneracy and spin orbital ordering in paramagnetic transition metal oxides sr 2 iro 4 versus sr 2 rho 4
Physical Review Letters, 2011Co-Authors: Cyril Martins, Markus Aichhorn, Loig Vaugier, Silke BiermannAbstract:We discuss the notions of Spin-Orbital polarization and ordering in paramagnetic materials, and address their consequences in transition-metal oxides. Extending the combined density functional and dynamical mean field theory scheme to the case of materials with large Spin-Orbit Interactions, we investigate the electronic excitations of the paramagnetic phases of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ and ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$. We show that the interplay of Spin-Orbit Interactions, structural distortions and Coulomb Interactions suppresses Spin-Orbital fluctuations. As a result, the room temperature phase of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ is a paramagnetic Spin-Orbitally ordered Mott insulator. In ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$, the effective Spin-Orbital degeneracy is reduced, but the material remains metallic, due to both, smaller Spin-Orbit and smaller Coulomb Interactions. The corresponding spectra are in excellent agreement with photoemission data. Finally, we make predictions for the spectra of paramagnetic ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.
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reduced effective spin orbital degeneracy and spin orbital ordering in paramagnetic transition metal oxides sr2iro4 versus sr2rho4
Physical Review Letters, 2011Co-Authors: Cyril Martins, Markus Aichhorn, Loig Vaugier, Silke BiermannAbstract:We discuss the notions of Spin-Orbital polarization and ordering in paramagnetic materials, and address their consequences in transition-metal oxides. Extending the combined density functional and dynamical mean field theory scheme to the case of materials with large Spin-Orbit Interactions, we investigate the electronic excitations of the paramagnetic phases of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ and ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$. We show that the interplay of Spin-Orbit Interactions, structural distortions and Coulomb Interactions suppresses Spin-Orbital fluctuations. As a result, the room temperature phase of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ is a paramagnetic Spin-Orbitally ordered Mott insulator. In ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$, the effective Spin-Orbital degeneracy is reduced, but the material remains metallic, due to both, smaller Spin-Orbit and smaller Coulomb Interactions. The corresponding spectra are in excellent agreement with photoemission data. Finally, we make predictions for the spectra of paramagnetic ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.
Markus Aichhorn - One of the best experts on this subject based on the ideXlab platform.
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reduced effective spin orbital degeneracy and spin orbital ordering in paramagnetic transition metal oxides sr 2 iro 4 versus sr 2 rho 4
Physical Review Letters, 2011Co-Authors: Cyril Martins, Markus Aichhorn, Loig Vaugier, Silke BiermannAbstract:We discuss the notions of Spin-Orbital polarization and ordering in paramagnetic materials, and address their consequences in transition-metal oxides. Extending the combined density functional and dynamical mean field theory scheme to the case of materials with large Spin-Orbit Interactions, we investigate the electronic excitations of the paramagnetic phases of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ and ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$. We show that the interplay of Spin-Orbit Interactions, structural distortions and Coulomb Interactions suppresses Spin-Orbital fluctuations. As a result, the room temperature phase of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ is a paramagnetic Spin-Orbitally ordered Mott insulator. In ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$, the effective Spin-Orbital degeneracy is reduced, but the material remains metallic, due to both, smaller Spin-Orbit and smaller Coulomb Interactions. The corresponding spectra are in excellent agreement with photoemission data. Finally, we make predictions for the spectra of paramagnetic ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.
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reduced effective spin orbital degeneracy and spin orbital ordering in paramagnetic transition metal oxides sr2iro4 versus sr2rho4
Physical Review Letters, 2011Co-Authors: Cyril Martins, Markus Aichhorn, Loig Vaugier, Silke BiermannAbstract:We discuss the notions of Spin-Orbital polarization and ordering in paramagnetic materials, and address their consequences in transition-metal oxides. Extending the combined density functional and dynamical mean field theory scheme to the case of materials with large Spin-Orbit Interactions, we investigate the electronic excitations of the paramagnetic phases of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ and ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$. We show that the interplay of Spin-Orbit Interactions, structural distortions and Coulomb Interactions suppresses Spin-Orbital fluctuations. As a result, the room temperature phase of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ is a paramagnetic Spin-Orbitally ordered Mott insulator. In ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$, the effective Spin-Orbital degeneracy is reduced, but the material remains metallic, due to both, smaller Spin-Orbit and smaller Coulomb Interactions. The corresponding spectra are in excellent agreement with photoemission data. Finally, we make predictions for the spectra of paramagnetic ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.
Jacob Linder - One of the best experts on this subject based on the ideXlab platform.
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long ranged triplet supercurrent in a single in plane ferromagnet with spin orbit coupled contacts to superconductors
Physical Review B, 2019Co-Authors: Johannes Rosok Eskilt, Morten Amundsen, Niladri Banerjee, Jacob LinderAbstract:© 2019 American Physical Society. By converting conventional spin-singlet Cooper pairs to polarized spin-triplet pairs, it is possible to sustain long-ranged spin-polarized supercurrents flowing through strong ferromagnets. Obtaining such a conversion via Spin-Orbit Interactions, rather than magnetic inhomogeneities, has recently been explored in the literature. A challenging aspect with regard to experimental detection has been that in order for Rashba Spin-Orbit Interactions, present, e.g., at interfaces due to inversion symmetry breaking, to generate such long-ranged supercurrents, an out-of-plane component of the magnetization is required. This limits the choice of materials and can induce vortices in the superconducting region complicating the interpretation of measurements. Therefore, it would be desirable to identify a way in which Rashba Spin-Orbit Interactions can induce long-ranged supercurrents for purely in-plane rotations of the magnetization. Here, we show that this is possible in a lateral Josephson junction where two superconducting electrodes are placed in contact with a ferromagnetic film via two thin, heavy normal metals. The magnitude of the supercurrent in such a setup becomes tunable by the in-plane magnetization angle when using only a single magnetic layer. These results could provide a new and simpler way to generate controllable spin-polarized supercurrents than previous experiments which utilized complicated magnetically textured Josephson junctions.
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long ranged triplet supercurrent in a single in plane ferromagnet with spin orbit coupled contacts to superconductors
arXiv: Superconductivity, 2019Co-Authors: Johannes Rosok Eskilt, Morten Amundsen, Niladri Banerjee, Jacob LinderAbstract:By converting conventional spin-singlet Cooper pairs to polarized spin-triplet pairs, it is possible to sustain long-ranged spin-polarized supercurrents flowing through strongly polarized ferromagnets. Obtaining such a conversion via Spin-Orbit Interactions, rather than magnetic inhomogeneities, has recently been explored in the literature. A challenging aspect with regard to experimental detection has been that in order for Rashba Spin-Orbit Interactions, present e.g. at interfaces due to inversion symmetry breaking, to generate such long-ranged supercurrents, an out-of-plane component of the magnetization is required. This limits the choice of materials and can induce vortices in the superconducting region complicating the interpretation of measurements. Therefore, it would be desirable to identify a way in which Rashba Spin-Orbit Interactions can induce long-ranged supercurrents for purely in-plane rotations of the magnetization. Here, we show that this is possible in a lateral Josephson junction where two superconducting electrodes are placed in contact with a ferromagnetic film via two thin, heavy normal metals. The magnitude of the supercurrent in such a setup becomes tunable by the in-plane magnetization angle when using only a single magnetic layer. These results could provide a new and simpler way to generate controllable spin-polarized supercurrents than previous experiments which utilized complicated magnetically textured Josephson junctions.
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anisotropic paramagnetic meissner effect by spin orbit coupling
Physical Review Letters, 2016Co-Authors: Camilla Espedal, Takehito Yokoyama, Jacob LinderAbstract:: Conventional s-wave superconductors repel an external magnetic field. However, a recent experiment [A. Di Bernardo et al., Phys. Rev. X 5, 041021 (2015)] has tailored the electromagnetic response of superconducting correlations via adjacent magnetic materials. We consider another route of altering the Meissner effect where Spin-Orbit Interactions induce an anisotropic Meissner response that changes sign depending on the field orientation. The tunable electromagnetic response opens new paths in the utilization of hybrid systems comprising magnets and superconductors.
Cyril Martins - One of the best experts on this subject based on the ideXlab platform.
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reduced effective spin orbital degeneracy and spin orbital ordering in paramagnetic transition metal oxides sr 2 iro 4 versus sr 2 rho 4
Physical Review Letters, 2011Co-Authors: Cyril Martins, Markus Aichhorn, Loig Vaugier, Silke BiermannAbstract:We discuss the notions of Spin-Orbital polarization and ordering in paramagnetic materials, and address their consequences in transition-metal oxides. Extending the combined density functional and dynamical mean field theory scheme to the case of materials with large Spin-Orbit Interactions, we investigate the electronic excitations of the paramagnetic phases of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ and ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$. We show that the interplay of Spin-Orbit Interactions, structural distortions and Coulomb Interactions suppresses Spin-Orbital fluctuations. As a result, the room temperature phase of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ is a paramagnetic Spin-Orbitally ordered Mott insulator. In ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$, the effective Spin-Orbital degeneracy is reduced, but the material remains metallic, due to both, smaller Spin-Orbit and smaller Coulomb Interactions. The corresponding spectra are in excellent agreement with photoemission data. Finally, we make predictions for the spectra of paramagnetic ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.
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reduced effective spin orbital degeneracy and spin orbital ordering in paramagnetic transition metal oxides sr2iro4 versus sr2rho4
Physical Review Letters, 2011Co-Authors: Cyril Martins, Markus Aichhorn, Loig Vaugier, Silke BiermannAbstract:We discuss the notions of Spin-Orbital polarization and ordering in paramagnetic materials, and address their consequences in transition-metal oxides. Extending the combined density functional and dynamical mean field theory scheme to the case of materials with large Spin-Orbit Interactions, we investigate the electronic excitations of the paramagnetic phases of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ and ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$. We show that the interplay of Spin-Orbit Interactions, structural distortions and Coulomb Interactions suppresses Spin-Orbital fluctuations. As a result, the room temperature phase of ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ is a paramagnetic Spin-Orbitally ordered Mott insulator. In ${\mathrm{Sr}}_{2}{\mathrm{RhO}}_{4}$, the effective Spin-Orbital degeneracy is reduced, but the material remains metallic, due to both, smaller Spin-Orbit and smaller Coulomb Interactions. The corresponding spectra are in excellent agreement with photoemission data. Finally, we make predictions for the spectra of paramagnetic ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$.
Allan H Macdonald - One of the best experts on this subject based on the ideXlab platform.
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photonic analogue of two dimensional topological insulators and helical one way edge transport in bi anisotropic metamaterials
arXiv: Materials Science, 2012Co-Authors: Alexander B Khanikaev, Allan H Macdonald, Hossein S Mousavi, Wangkong Tse, Mehdi Kargarian, Gennady ShvetsAbstract:Recent progress in understanding the topological properties of condensed matter has led to the discovery of time-reversal invariant topological insulators. Because of limitations imposed by nature, topologically non-trivial electronic order seems to be uncommon except in small-band-gap semiconductors with strong Spin-Orbit Interactions. In this Article we show that artificial electromagnetic structures, known as metamaterials, provide an attractive platform for designing photonic analogues of topological insulators. We demonstrate that a judicious choice of the metamaterial parameters can create photonic phases that support a pair of helical edge states, and that these edge states enable one-way photonic transport that is robust against disorder.
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quantum hall ferromagnetism in graphene
Physical Review Letters, 2006Co-Authors: Kentaro Nomura, Allan H MacdonaldAbstract:Graphene is a two-dimensional carbon material with a honeycomb lattice and Dirac-like low-energy excitations. When Zeeman and Spin-Orbit Interactions are neglected, its Landau levels are fourfold degenerate, explaining the $4{e}^{2}/h$ separation between quantized Hall conductivity values seen in recent experiments. In this Letter we derive a criterion for the occurrence of interaction-driven quantum Hall effects near intermediate integer values of ${e}^{2}/h$ due to charge gaps in broken symmetry states.
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theory of spin charge coupled transport in a two dimensional electron gas with rashba spin orbit Interactions
Physical Review B, 2004Co-Authors: A A Burkov, Alvaro S Nunez, Allan H MacdonaldAbstract:We use microscopic linear response theory to derive a set of equations that provide a complete description of coupled spin and charge diffusive transport in a two-dimensional electron gas (2DEG) with the Rashba Spin-Orbit (SO) interaction. These equations capture a number of interrelated effects including spin accumulation and diffusion, Dyakonov-Perel spin relaxation, magnetoelectric, and spin-galvanic effects. They can be used under very general circumstances to model transport experiments in 2DEG systems that involve either electrical or optical spin injection. We comment on the relationship between these equations and the exact spin and charge density operator equations of motion. As an example of the application of our equations, we consider a simple electrical spin injection experiment and show that a voltage will develop between two ferromagnetic contacts if a spin-polarized current is injected into a 2DEG, that depends on the relative magnetization orientation of the contacts. This voltage is present even when the separation between the contacts is larger than the spin diffusion length.
