0000000000253209

AUTHOR

Mike A. Lund

showing 3 related works from this author

Large surface magnetization in noncentrosymmetric antiferromagnets

2020

Thin-film antiferromagnets (AFs) with Rashba spin-orbit coupling are theoretically investigated. We demonstrate that the relativistic Dzyaloshinskii-Moriya interaction (DMI) produces a large surface magnetization and a boundary-driven twist state in the antiferromagnetic N\' eel vector. We predict a magnetization on the order of $2.3\cdot 10^4$~A/m, which is comparable to the magnetization of ferromagnetic semiconductors. Importantly, the magnetization is characterized by ultra-fast terahertz dynamics and provides new approaches for efficiently probing and controlling the spin dynamics of AFs as well as detecting the antiferromagnetic DMI. Notably, the magnetization does not lead to any str…

PhysicsCondensed Matter - Materials ScienceCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed matter physicsTerahertz radiationMagnetic monopoleMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciencesOrder (ring theory)02 engineering and technologyPhysik (inkl. Astronomie)021001 nanoscience & nanotechnologyCoupling (probability)01 natural sciencesMagnetic fieldMagnetizationMesoscale and Nanoscale Physics (cond-mat.mes-hall)0103 physical sciencesAntiferromagnetismCondensed Matter::Strongly Correlated ElectronsTwist010306 general physics0210 nano-technologyPhysical Review B
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Cross-sublattice Spin Pumping and Magnon Level Attraction in van der Waals Antiferromagnets

2020

We theoretically study spin pumping from a layered van der Waals antiferromagnet in its canted ground state into an adjacent normal metal. We find that the resulting dc spin pumping current bears contributions along all spin directions. Our analysis allows for detecting intra- and cross-sublattice spin-mixing conductances via measuring the two in-plane spin current components. We further show that sublattice symmetry-breaking Gilbert damping can be realized via interface engineering and induces a dissipative coupling between the optical and acoustic magnon modes. This realizes magnon level attraction and exceptional points in the system. Furthermore, the dissipative coupling and cross-subla…

FOS: Physical sciences02 engineering and technology01 natural sciencessymbols.namesake0103 physical sciencesMesoscale and Nanoscale Physics (cond-mat.mes-hall)Antiferromagnetism010306 general physicsSpin-½CouplingPhysicsCondensed Matter - Materials ScienceSpin pumpingCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed matter physicsMagnonMaterials Science (cond-mat.mtrl-sci)021001 nanoscience & nanotechnologyCondensed Matter - Other Condensed MatterDissipative systemsymbolsCondensed Matter::Strongly Correlated Electronsvan der Waals force0210 nano-technologyGround stateOther Condensed Matter (cond-mat.other)
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Spin pumping in noncollinear antiferromagnets

2021

The ac spin pumping of noncollinear antiferromagnets is theoretically investigated. Starting from an effective action description of the spin system, we derive the Onsager coefficients connecting the spin pumping and spin-transfer torque associated with the dynamics of the SO(3)-valued antiferromagnetic order parameter. Our theory is applied to a kagome antiferromagnet resonantly driven by a uniform external magnetic field. We demonstrate that the reactive (dissipative) spin-transfer torque parameter can be extracted from the pumped ac spin current in-phase (in quadrature) with the driving field. Furthermore, we find that the three spin-wave bands of the kagome AF generate spin currents wit…

PhysicsSpin pumpingCondensed Matter - Materials ScienceField (physics)Condensed matter physicsCondensed Matter - Mesoscale and Nanoscale PhysicsOrthogonal polarization spectral imagingPhase (waves)Materials Science (cond-mat.mtrl-sci)FOS: Physical sciencesMagnetic fieldMesoscale and Nanoscale Physics (cond-mat.mes-hall)Dissipative systemAntiferromagnetismCondensed Matter::Strongly Correlated ElectronsSpin-½
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