0000000000736881

AUTHOR

Zdeněk Kašpar

showing 2 related works from this author

Terahertz electrical writing speed in an antiferromagnetic memory

2018

The speed of writing of state-of-the-art ferromagnetic memories is physically limited by an intrinsic gigahertz threshold. Recently, realization of memory devices based on antiferromagnets, in which spin directions periodically alternate from one atomic lattice site to the next has moved research in an alternative direction. We experimentally demonstrate at room temperature that the speed of reversible electrical writing in a memory device can be scaled up to terahertz using an antiferromagnet. A current-induced spin-torque mechanism is responsible for the switching in our memory devices throughout the 12-order-of-magnitude range of writing speeds from hertz to terahertz. Our work opens the…

Terahertz radiationPhysics::Optics02 engineering and technologyHardware_PERFORMANCEANDRELIABILITY01 natural sciences530Computer Science::Hardware ArchitectureHertz0103 physical sciencesHardware_INTEGRATEDCIRCUITSAntiferromagnetismAtomic lattice010306 general physicsResearch ArticlesSpin-½PhysicsMultidisciplinarybusiness.industrySciAdv r-articles021001 nanoscience & nanotechnologyelectrical writingFerromagnetismApplied Sciences and Engineeringwriting speedComputer ScienceOptoelectronicsCondensed Matter::Strongly Correlated Electronsantiferromagnetic memory0210 nano-technologybusinessRealization (systems)Research ArticleScience Advances
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Temperature-dependent resistivity and anomalous Hall effect in NiMnSb from first principles

2019

We present implementation of the alloy analogy model within fully relativistic density-functional theory with the coherent potential approximation for a treatment of nonzero temperatures. We calculate contributions of phonons and magnetic and chemical disorder to the temperature-dependent resistivity, anomalous Hall conductivity (AHC), and spin-resolved conductivity in ferromagnetic half-Heusler NiMnSb. Our electrical transport calculations with combined scattering effects agree well with experimental literature for Ni-rich NiMnSb with 1--2% Ni impurities on Mn sublattice. The calculated AHC is dominated by the Fermi surface term in the Kubo-Bastin formula. Moreover, the AHC as a function o…

Materials scienceCondensed matter physicsSpin polarizationPhononFermi surface02 engineering and technologyConductivity021001 nanoscience & nanotechnology01 natural sciencesCondensed Matter::Materials ScienceFerromagnetismHall effectElectrical resistivity and conductivity0103 physical sciencesCoherent potential approximation010306 general physics0210 nano-technologyPhysical Review B
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