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Maniv, Eran

Publications and source records attributed to Maniv, Eran.

8 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Long-range, non-local switching of spin textures in a frustrated antiferromagnet

Abstract Antiferromagnetic spintronics is an emerging area of quantum technologies that leverage the coupling between spin and orbital degrees of freedom in exotic materials. Spin-orbit interactions allow spin or angular momentum to be injected via electrical stimuli to manipulate the spin texture of a material, enabling the storage of information and energy. In general, the physical process is intrinsically local: spin is carried by an electrical current, imparted into the magnetic system, and the spin texture will then rotate in the region of current flow. In this study, we show that spin information can be transported and stored “non-locally" in the material Fe x NbS 2 . We propose that collective modes can manipulate the spin texture away from the flowing current, an effect amplified by strong magnetoelastic coupling of the ordered state. This suggests a novel way to store and transport spin information in strongly spin-orbit coupled magnetic systems.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Antiferromagnetic memory storage devices from magnetic transition metal dichalcogenides

Switchable antiferromagnetic (AFM) memory devices are provided based on magnetically intercalated transition metal dichalcogenides (TMDs) of the form AxMC2, where A is a magnetic element of stoichiometry x between 0 and 1, M is a transition metal of stoichiometry 1, and C is a chalcogen of stoichiometry 2. Memory storage is achieved by fabricating these materials into crosses of two or more bars and driving DC current pulses along the bars to rotate the AFM order to a fixed angle with respect to the current pulse. Application of current pulses along different bars can switch the AFM order between multiple directions. Standard resistance measurements can detect the orientation of the AFM order as high or low resistance states. The state of the device can be set by the input current pulses, and read-out by the resistance measurement, forming a non-volatile, AFM memory storage bit.

Analytis, James G.↗
DOE OSTI2021

Evidence for a delocalization quantum phase transition without symmetry breaking in CeCoIn 5

The study of quantum phase transitions that are not clearly associated with broken symmetry is a major effort in condensed matter physics, particularly in regard to the problem of high-temperature superconductivity, for which such transitions are thought to underlie the mechanism of superconductivity itself. Here we argue that the putative quantum critical point in the prototypical unconventional superconductor CeCoIn 5 is characterized by the delocalization of electrons in a transition that connects two Fermi surfaces of different volumes, with no apparent broken symmetry. Drawing on established theory of f-electron metals, we discuss an interpretation for such a transition that involves the fractionalization of spin and charge, a model that effectively describes the anomalous transport behavior we measured for the Hall effect.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Exchange bias due to coupling between coexisting antiferromagnetic and spin-glass orders

Exchange bias is a property of widespread technological utility, but its underlying mechanism remains elusive, in part because it is rooted in the interaction of coexisting order parameters in the presence of complex magnetic disorder. In this study we show that a giant exchange bias housed within a spin-glass phase arises in a disordered antiferromagnet. The magnitude and robustness of the exchange bias emerges from a convolution of two energetic landscapes, namely the highly degenerate landscape of the spin glass biased by the sublattice spin configuration of the antiferromagnet. The former provides a source of uncompensated moment, whereas the latter provides a mechanism for its pinning, which leads to the exchange bias. Tuning the relative strengths of the spin-glass and antiferromagnetic order parameters reveals a principle for tailoring the exchange bias, with potential applications to spintronic technologies.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Three-state nematicity in the triangular lattice antiferromagnet Fe 1/3 NbS 2

Nematic order is the breaking of rotational symmetry in the presence of translational invariance. While originally defined in the context of liquid crystals, the concept of nematic order has arisen in crystalline matter with discrete rotational symmetry, most prominently in the tetragonal Fe-based superconductors where the parent state is four-fold symmetric. In this case the nematic director takes on only two directions, and the order parameter in such 'Ising-nematic' systems is a simple scalar. In this study, using a spatially resolved optical polarimetry technique, we show that a qualitatively distinct nematic state arises in the triangular lattice antiferromagnet Fe 1/3 NbS 2 . The crucial difference is that the nematic order on the triangular lattice is a Z 3 or three-state Potts-nematic order parameter. As a consequence, the anisotropy axes of response functions such as the resistivity tensor can be continuously reoriented by external perturbations. This discovery lays the groundwork for devices that exploit analogies with nematic liquid crystals.

36 MATERIALS SCIENCE↗